Alpha淀粉酶[米麴菌]
英文名：α-Amylase (Aspergillus oryzae)
货号：E-ANAAM
规格：20000 Units
High purity alpha-Amylase (A. oryzae) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 3.2.1.1
CAZy Family: GH13
From Aspergillus oryzae. Electrophoretically homogeneous.
In 3.2 M ammonium sulphate.
Specific activity: ~ 126 U/mg
Stable at 4oC for > 4 years. As used in Megazyme Starch Damage method.
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Alpha淀粉酶[猪胰腺]
英文名：α-Amylase (Porcine Pancreatic)
货号：E-PANAA-3G
规格：3g
High purity alpha-Amylase (Porcine Pancreatic) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 3.2.1.1
CAZy Family: GH13
From porcine pancreas. Partially purified. Free flowing powder.
Specific activity: ca. 100,000 U/g (40oC, Ceralpha reagent).
Stable at -20oC for > 4 years.
For use in total dietary fiber (including resistant starch) assay procedure.
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上海金畔生物科技有限公司提供Megazyme总膳食纤维检测试剂盒 规格：200次检测
产品名称：膳食纤维总量检测试剂盒
英文名称：Toal Dietary Fibre Assay Kit
货号：ADM0033
型号规格：200次
优点：
使用的酶为高纯度酶，酶之间没有干扰效应的，且具有标准化酶活力。Megazyme 淀粉葡糖甘酶完全没有纤维素酶的活性，但其他公司生产的酶常被此活性污染，那样会导致β-葡聚糖被溶解和含量经常被低估。所有的Megazyme酶都是液态即用型。
应用方法：
总膳食纤维是采用经过干燥和脱脂（如果脂肪含量>10%）的复样为样品。样品用热稳定的α-淀粉酶在100℃下处理以使淀粉成胶状，水解和解聚；用蛋白酶（使蛋白溶解和解聚）和淀粉葡糖甘酶（将淀粉碎片水解成葡萄糖（来自淀粉））在60℃下处理；然后用4倍体积的乙醇处理以沉淀可溶性纤维，去除解聚的蛋白和葡萄糖（来自淀粉）。然后残留物分别用78%乙醇，95%乙醇，丙酮洗涤，再干燥，称重。一份复样用于蛋白分析，另外一份在525℃下孵育以测定灰分，总TDF就是被过滤和干燥的残留物的重量减去蛋白和灰分的重量。
适用范围：
应用于谷粒，果蔬，谷物和水果型产品食品。 酶纯度和标准化：
α-淀粉酶（E-BLAAM）的酶活为3，000UmL(Ceralpha 法)；蛋白酶的浓度为50mg/mL(~350 酪氨酸U/mL)；淀粉葡糖甘酶单位为200U/mL（底物为对硝基苯基β-麦芽糖苷）或单位3300U/ mL（底物为可溶性淀粉），淀粉葡糖甘酶酶活为传统TDF分析使用的150%。
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上海金畔生物科技有限公司
订货热线：15221999938
网 址： www.jinpanbio.com
金畔博客：www.jinpanbio.cn
Email：sales@jinpanbio.com
氨[快速]检测试剂盒
英文名：Ammonia (Rapid) Assay Kit
货号：K-AMIAR
规格：96 assays (manual) /960 assays (microplate
分析物意义: 常见食品的组分
Megazyme检测试剂盒优点: K-AMIAR ，反应快（3 min，室温）。
适用于手工和自动分析仪进行检测。试剂稳定
For the rapid assay of ammonia in all samples, including grape juice and wine. Content:96 assays per kit
UV-method for the determination of Ammonia in foodstuffs,
beverages and other materials
Principle:
(microbial glutamate dehydrogenase)
(1) 2-Oxoglutarate + NADPH + NH4+ → L-glutamic acid + NADP+
+ H2O
Kit size: 96 assays (manual) / 960 (microplate)
/ 960 (auto-analyser)
Method: Spectrophotometric at 340 nm
Reaction time: ~ 3 min
Detection limit: 0.07 mg/L
Application examples:
Grape juice, wine, fruit juices, soft drinks, dairy products (e.g. milk),
dietetic food, soy sauce, eggs and egg products, cheese, meat,
processed meat, seafood, bakery products (and baking agents),
fertilisers, pharmaceuticals, tobacco, cosmetics, water, Kjeldahl
analysis, paper (and cardboard), water and other materials
(e.g. biological cultures, samples, etc.)
Method recognition:
Methods based on this principle have been accepted by MEBAK
Advantages
Q1. There is an issue with the performance of the kit; the results are not as expected.
If you suspect that the Megazyme test kit is not performing as expected such that expected results are not obtained please do the following:
The pH of the assay solution after the sample is added should be the same as that of the assay buffer that is supplied with the kit.
Low sample volumes (e.g. 0.1 mL) are not likely to affect the pH of the assay solution and therefore may not require pH adjustment.
Samples above 0.1 mL are more likely to affect the pH of the assay solution and therefore the pH of these samples should be adjusted as described in the data booklet, prior to addition to the assay.
Sometimes the addition of the last assay component can cause a small negative absorbance change in the blank samples due to a dilution effect and in such cases it is recommended that the real absorbance values be used in the calculation of results.
Yes, assuming that the concentration of the analyte in the sample (after sample preparation) is above the limit of detection for the kit. It may be sufficient to use the sample directly in the assay after clarification by centrifugation/filtering followed by dilution (if required) in distilled water.
The final pH of the kit assay after the sample is added should not change from what it should be (as stated in the kit for the assay buffer). If it does change then the sample will require pH adjustment. In most cases the sample volume being used is low relative to the final assay volume and in this case the pH of the kit assay is unlikely to be affected.
Where the amount of analyte in a liquid sample is unknown, it is recommended that a range of sample dilutions are prepared with the aim of obtaining an absorbance change in the assay that is within the linear range.
Where solid samples are analysed, the weight of sample per volume of water used for sample extraction/preparation can be altered to suit, as can the dilution of the extracted sample prior to the addition of the assay, as per liquid samples.
For users who are not familiar with how to use the Megazyme tests kits then it is recommended that they follow this example, e.g. D-Fructose/D-Glucose Assay kit K-FRUGL (http://secure.megazyme.com/D-Fructose-D-Glucose-Assay-Kit):
1. The kit components are listed on pages 2-3 of the kit booklet.
2. Prepare the kit reagents as described on page 3.
3. For separate measurements of glucose and fructose follow procedure A on page 4.
4. Pipette the volumes listed for water, sample, solution 1 and solution 2 into 3 mL, 1 cm pathlength cuvettes. Duplicate sample assays and duplicate blanks are recommended. Mix the contents of each cuvette by inversion (seal the cuvette using parafilm or a plastic cuvette cap – do not use a finger) then after ~3 min record the first absorbance reading of each cuvette at 340 nm (this is reading A1).
5. Then add suspension 3 and mix the contents of each cuvette by inversion. Incubate for 5 minutes then record the absorbance reading of each cuvette at 340 nm (this is reading A2). NB. It is essential that the reaction is compete. To assess this, record the absorbances at ~ 2 minute intervals and until the absorbance plateaus. A stable absorbance indicates that the reaction is complete. If the absorbance continues to increase then continue to record absorbances until it plateaus and only then record absorbance reading A2.
6. Then add suspension 4 and mix the contents of each cuvette by inversion. Incubate for 5 minutes then take absorbance reading of each cuvette at 340 nm (this is reading A3). NB. As above, assess that the reaction has completed by take subsequent readings at ~2 min intervals.
7. For simple, automated results analysis, input the absorbance readings (A1, A2, A3) for samples and blanks into the K-FRUGL MegaCalc.
To ensure that the assay is working, and being performed correctly it is recommend that the test is performed using the standard sample that is provided with the kit and to obtain the expected values before proceeding to test real samples.
It is recommend that new users also watch this video which highlights how to perform the assays.
Many of the other Megazyme test kits follow a similar format.
If there are any concerns with any kit components, the first thing to do is to test the standard sample (control sample) that is supplied with the kit and ensure that the expected value (within the accepted variation) is obtained before testing any precious samples. This must be done using the procedure provided in the kit booklet without any modifications to the procedure. If there are still doubts about the results using the standard sample in the kit then send example results in the MegaCalc spread sheet to your product supplier (Megazyme or your local Megazyme distributor).
The volume/weight of sample and total volume of the extract can be modified to suit the sample. This will ultimately be dictated by the amount of analyte of interest in the sample and may require empirical determination. For low levels of analyte the sample:extract volume ratio can be increased (i.e. increase the sample and/or decrease the total extraction volume).
Alternatively, for samples with low concentrations of analyte, a larger sample volume can be added to the kit assay. When altering the sample volume adjust the distilled water volume added to the assay accordingly so that the total assay volume is not altered.
For samples with low concentrations of analyte the sample volume used in the kit assay can be increased to increase sensitivity. When doing this the water volume is adjusted to retain the same final assay volume. This is critical for the manual assay format because the assay volume and sample volume are used in the calculation of results.
The majority of the Megazyme test kits are developed to work in cuvettes using the manual assay format, however the assay can be converted for use in a 96-well microplate format. To do this the assay volumes for the manual cuvette format are reduced by 10-fold. The calculation of results for the manual assay format uses a 1 cm path-length, however the path-length in the microplate is not 1 cm and therefore the MegaCalc spreadsheet or the calculation provided in the kit booklet for the manual format cannot be used for the micropalate format unless the microplate reader being used can.
There a 3 main methods for calculation of results using the microplate format:
For samples with low concentrations of analyte the sample volume used in the kit assay can be increased to increase sensitivity. When doing this the water volume is adjusted to retain the same final assay volume. This is critical for the manual assay format because the assay volume and sample volume are used in the calculation of results.
The volume/weight of sample and total volume of the extract can be modified to suit the sample. This will ultimately be dictated by the amount of analyte of interest in the sample and may require empirical determination. For low levels of analyte the sample:extract volume ratio can be increased (i.e. increase the sample and/or decrease the total extraction volume).
Alternatively, for samples with low concentrations of analyte, a larger sample volume can be added to the kit assay. When altering the sample volume adjust the distilled water volume added to the assay accordingly so that the total assay volume is not altered.
The test kit is extremely accurate – at Megazyme the quality control criteria for accuracy and repeatability is to be within 2% of the expected value using pure analytes.
However, the level of accuracy is obviously analyst and sample dependent.
Yes, instead of adding 2 μL of enzyme suspension an alternative is to dilute the enzyme and add a larger volume to the microplate assay.
Dilute the assay buffer 10-fold with distilled water and use this as the diluent to dilute an aliquot of the enzyme suspension also by 10-fold. Instead of 2 μL, use 20 μL of the diluted enzyme in the microplate assay.
Yes. Samples with the lower concentrations of analyte will generate a lower absorbance change. For samples with low concentrations of analyte, a larger sample volume can be used in the assay to increase the absorbance change and thereby increase sensitivity of the assay. When doing this the increased volume of the sample should be subtracted from the distilled water volume that is added to the assay so that the total assay volume is unaltered. The increase sample volume should also be accounted for when calculating final results.
No. The 0.1 change of absorbance is only a recommendation. The lowest acceptable change in absorbance can is dictated by the analyst and equipment (i.e. pipettes and spectrophotometer) and therefore can be can be determined by the user. With accurate pipetting, absorbance changes as low as 0.02 can be used accurately.
If a change in absorbance above 0.1 is required but cannot be achieved due to low concentrations of analyte in a sample, this can be overcome by using a larger sample volume in the assay to increase the absorbance change and thereby increase sensitivity of the assay. When doing this the increased volume of the sample should be subtracted from the distilled water volume that is added to the assay so that the total assay volume is unaltered. The increase sample volume should also be accounted for when calculating final results.
L-谷氨酸[谷氨酸盐/谷氨酸酯/味精/谷氨酸单钠]检测试剂盒
英文名：L-Glutamic Acid Assay Kit
货号：K-GLUT
规格：60 assays (manual) /
分析物意义：常见的天然食品组分，例如在奶酪和番茄中或调味剂中，如味精
Megazyme检测试剂盒优点：提供的硫辛酰胺脱氢酶是稳定的悬浮液而不是可溶性粉末，从而减少了酶的浪费
The L-Glutamic Acid test kit is a simple, reliable, rapid and accurate method for the measurement and analysis of L-glutamate (MSG) in foodstuffs.
Suitable for manual, auto-analyser and microplate formats.
Colourimetric method for the determination of L-Glutamic Acid
(Monosodium Glutamate; MSG) in foodstuffs and other materials
Principle:
(beef liver glutamate dehydrogenase)
(1) L-Glutamic acid + NAD+ + H2O ↔ 2-oxoglutarate + NADH + NH4+
(diaphorase)
(2) INT + NADH + H+ → NAD+ + INT-formazan
Kit size: 60 assays (manual) / 600 (microplate)
/ 700 (auto-analyser)
Method: Spectrophotometric at 492 nm
Reaction time: ~ 9 min
Detection limit: 0.21 mg/L
Application examples:
Fruit and vegetables (e.g. tomato), processed fruit and vegetables
(e.g. tomato puree / juice, ketchup, soy sauce), condiments, processed
meat products (e.g. extracts, bouillon and sausages), soup, pharmaceuticals
and other materials (e.g. biological cultures, samples, etc.)
Method recognition:
Methods based on this principle have been accepted by ISO, GOST
and NMKL
Advantages
Samples that contain cysteine levels higher than 1 mM will not generate results within the required specification for the K-GLUT assay.
The pH of the assay solution after the sample is added should be the same as that of the assay buffer that is supplied with the kit.
Low sample volumes (e.g. 0.1 mL) are not likely to affect the pH of the assay solution and therefore may not require pH adjustment.
Samples above 0.1 mL are more likely to affect the pH of the assay solution and therefore the pH of these samples should be adjusted as described in the data booklet, prior to addition to the assay.
If you suspect that the Megazyme test kit is not performing as expected such that expected results are not obtained please do the following:
Where the amount of analyte in a liquid sample is unknown, it is recommended that a range of sample dilutions are prepared with the aim of obtaining an absorbance change in the assay that is within the linear range.
Where solid samples are analysed, the weight of sample per volume of water used for sample extraction/preparation can be altered to suit, as can the dilution of the extracted sample prior to the addition of the assay, as per liquid samples.
If there are any concerns with any kit components, the first thing to do is to test the standard sample (control sample) that is supplied with the kit and ensure that the expected value (within the accepted variation) is obtained before testing any precious samples. This must be done using the procedure provided in the kit booklet without any modifications to the procedure. If there are still doubts about the results using the standard sample in the kit then send example results in the MegaCalc spread sheet to your product supplier (Megazyme or your local Megazyme distributor).
For samples with low concentrations of analyte the sample volume used in the kit assay can be increased to increase sensitivity. When doing this the water volume is adjusted to retain the same final assay volume. This is critical for the manual assay format because the assay volume and sample volume are used in the calculation of results.
The volume/weight of sample and total volume of the extract can be modified to suit the sample. This will ultimately be dictated by the amount of analyte of interest in the sample and may require empirical determination. For low levels of analyte the sample:extract volume ratio can be increased (i.e. increase the sample and/or decrease the total extraction volume).
Alternatively, for samples with low concentrations of analyte, a larger sample volume can be added to the kit assay. When altering the sample volume adjust the distilled water volume added to the assay accordingly so that the total assay volume is not altered.
The kit assay may work for biological fluids assuming that inositol is present above the limit of detection for the kit after any sample preparation (if required). Centrifugation of the samples and use of the supernatant directly in the kit assay (with appropriate dilution in distilled water) may be sufficient. However, if required a more stringent sample preparation method may be required and examples are provided at the following link:http://www.megazyme.com/docs/analytical-applications-downloads/biological_samples_111109.pdf?sfvrsn=2
The test kit has not been tested using biological fluids as samples because it is not marketed or registered as a medical device. This will therefore require your own validation.
The majority of the Megazyme test kits are developed to work in cuvettes using the manual assay format, however the assay can be converted for use in a 96-well microplate format. To do this the assay volumes for the manual cuvette format are reduced by 10-fold. The calculation of results for the manual assay format uses a 1 cm path-length, however the path-length in the microplate is not 1 cm and therefore the MegaCalc spreadsheet or the calculation provided in the kit booklet for the manual format cannot be used for the micropalate format unless the microplate reader being used can.
There a 3 main methods for calculation of results using the microplate format:
The test kit is extremely accurate – at Megazyme the quality control criteria for accuracy and repeatability is to be within 2% of the expected value using pure analytes.
However, the level of accuracy is obviously analyst and sample dependent.
Some samples can react with the INT in the assay and cause a non-enzymatic creep reaction.
The 3rd worksheet in the MegaCalc is used to account for any creep reaction in your results.
No. The 0.1 change of absorbance is only a recommendation. The lowest acceptable change in absorbance can is dictated by the analyst and equipment (i.e. pipettes and spectrophotometer) and therefore can be can be determined by the user. With accurate pipetting, absorbance changes as low as 0.02 can be used accurately.
If a change in absorbance above 0.1 is required but cannot be achieved due to low concentrations of analyte in a sample, this can be overcome by using a larger sample volume in the assay to increase the absorbance change and thereby increase sensitivity of the assay. When doing this the increased volume of the sample should be subtracted from the distilled water volume that is added to the assay so that the total assay volume is unaltered. The increase sample volume should also be accounted for when calculating final results.
Yes. Samples with the lower concentrations of analyte will generate a lower absorbance change. For samples with low concentrations of analyte, a larger sample volume can be used in the assay to increase the absorbance change and thereby increase sensitivity of the assay. When doing this the increased volume of the sample should be subtracted from the distilled water volume that is added to the assay so that the total assay volume is unaltered. The increase sample volume should also be accounted for when calculating final results.
乳果糖检测试剂盒
英文名：Lactulose Assay Kit
货号：K-LACTUL
规格：50 assays
Megazyme乳果糖检测试剂盒采用酶法分析原理，可定量检测鲜奶、UHT奶、浓缩乳和奶粉等各种乳品中的乳果糖。与农业部新标准采用相同的检测原理和方法该试剂盒采用ISO方法11285：2004，经过改进后，更加快速和灵敏灵敏度是传统己糖激酶法的两倍成本低试剂配制后可稳定保存2年采用试剂盒形式，包含检测必需的所有酶提供计算软件，使数据处理更方便包含标准品
The Lactulose Assay Kit is suitable for the specific, rapid and sensitive measurement and analysis of lactulose in milk and milk-based samples. Reagents included in this kit may also be prepared for use in the procedure described by ISO Method 11285:2004.
UV-method for the determination of Lactulose in milk and
foodstuffs containing dairy products
Principle:
(β-galactosidase)
(1) Lactulose + H2O → D-galactose + D-fructose
(glucose oxidase + catalase + H2O2)
(2) D-Glucose + H2O + O2 → D-gluconic acid + H2O2
(hexokinase)
(3) D-Fructose + ATP → F-6-P + ADP
(phosphoglucose isomerase)
(4) F-6-P → G-6-P
(glucose-6-phosphate dehydrogenase)
(5) G-6-P + NADP+ → gluconate-6-phosphate + NADPH + H+
(gluconate-6-phosphate dehydrogenase)
(6) Gluconate-6-phosphate + NADP+ → ribulose-5-phosphate + NADPH
+ CO2 + H+
Kit size: 50 assays
Method: Spectrophotometric at 340 nm
Reaction time: ~ 120 min
Detection limit: 4.8 mg/L
Application examples:
Milk, dairy products and foods containing milk
Method recognition: Novel method
Advantages
Q1. Sometimes a negative absorbance change is obtained for the blank samples, is this normal? Should the real value (negative absorbance change) or “0” be used in the calculation of results?
Sometimes the addition of the last assay component can cause a small negative absorbance change in the blank samples due to a dilution effect and in such cases it is recommended that the real absorbance values be used in the calculation of results.
Samples that generate absorbance values A2 – A1 of 0.3 should be diluted in distilled water prior to the Sample Preparation (section A, page 7) and the second incubation of step 2 increased (glucose oxidase / catalase) to 30 min.
Some critical steps of the assay are as follows:
A2 should be read after approximately 10 min and you should ensure that the reaction has finished, i.e. measure the absorbance until it stops increasing. (Slight increases in absorbance of 0.001/min or less are acceptable).
The supernatants from both steps (1 and 2) of A. Sample Preparation should be clear.
The K-LACTUL kit will measure lactulose in most samples however it is the sample preparation prior to the Enzymatic Determination Reaction that is important. Megazyme has only tested milk-based samples, however most samples that do not contain high protein levels may work using the same standard procedure as described in the K-LACTUL data booklet. Samples containing very high levels of free fructose may not work.
The pH of the assay solution after the sample is added should be the same as that of the assay buffer that is supplied with the kit.
Low sample volumes (e.g. 0.1 mL) are not likely to affect the pH of the assay solution and therefore may not require pH adjustment.
Samples above 0.1 mL are more likely to affect the pH of the assay solution and therefore the pH of these samples should be adjusted as described in the data booklet, prior to addition to the assay.
If you suspect that the Megazyme test kit is not performing as expected such that expected results are not obtained please do the following:
If it is suspected that the measurements of K-LACTUL are not correct and there is doubt regarding the performance of the kit then the following steps should be checked.
1. Check that the cuvettes are 1.5 mL microcuvettes and that the volume of the liquid in the cuvettes is high enough for the spectrophotometer.
2. Check the temperature of the reactions is correct.
Using the standard lactulose/fructose solution (bottle 8) that is supplied with the kit will help determine where issues are occurring with the measurement of lactulose samples. The obvious steps where issues may occur are: A. Sample Preparation (page 7 K-LACTUL booklet) and B. Enzymatic Determination Reaction (page 8 K-LACTUL booklet).
3. The performance of K-LACTUL can be tested as follows:
(A. Sample Preparation (page 7 K-LACTUL booklet)
Use 0.5 mL of the standard lactulose /fructose solution (Bottle 8) which contains 0.1 mg/mL lactulose and 0.05 mg/mL fructose. The typical individual absorbance values are: A1 = 0.2, A2 = 0.2, A3 = 1.0. This should generate a final absorbance difference of (A3-A2) of approximately 0.8 (Note: this measurement includes the lactulose and fructose measurement and is not just lactulose content only).
Note: If the correct values are obtained for the performance of K-LACTUL then there is no need to check the performance of the Enzymatic Determination Reaction step separately.
4. The performance of the Enzymatic Determination Reaction step can be tested separately as follows:
B. Enzymatic Determination Reaction (page 8 K-LACTUL booklet)
This test uses 0.1 mL of the standard lactulose /fructose solution (Bottle 8) which contains 0.05 mg/mL fructose. This is equivalent to 5 μg of fructose added to the cuvette and should generate an absorbance difference (A3-A2) of approximately 0.3. If this absorbance difference is obtained then it can be concluded that the step is performing correctly.
B. ENZYMATIC DETERMINATION REACTION:
Wavelength: 340 nm
Cuvette: 1 cm light path (glass or plastic; 1.5 mL semi-micro)
Final volume: 1.16 mL
Sample solution: 0.65-65 μg of lactulose per cuvette (in 0.1-1.0 mL sample volume)
Read against air (without cuvette in the light path) or against water Pipette
|
Pipette into cuvettes |
Sample |
Blank |
|
standard 8 (lactulose/fructose solution) distilled water solution 3 (imidazole buffer) solution 4 (NADP+/ATP) |
0.10 mL 0.90 mL 0.05 mL 0.05 mL |
– 1.00 mL 0.05 mL 0.05 mL |
|
Mix*, read absorbance of the solutions (A1) after approx. 3 min and start the reactions by addition of: |
||
|
suspension 5 (HK/G-6-PDH) suspension 6 (6-PGDH) |
0.02 mL 0.02 mL |
0.02 mL 0.02 mL |
|
Mix*, read absorbance of the solutions (A2) at the end of the reaction (approx. 10 min). Then add: |
||
|
suspension 7 (PGI) |
0.02 mL |
0.02 mL |
|
Mix*, read absorbance of the solutions (A3) at the end of the reaction (approx. 15 min). |
||
* for example with a plastic spatula or by gentle inversion after sealing the cuvette with a cuvette cap or Parafilm®.
Where the amount of analyte in a liquid sample is unknown, it is recommended that a range of sample dilutions are prepared with the aim of obtaining an absorbance change in the assay that is within the linear range.
Where solid samples are analysed, the weight of sample per volume of water used for sample extraction/preparation can be altered to suit, as can the dilution of the extracted sample prior to the addition of the assay, as per liquid samples.
If there are any concerns with any kit components, the first thing to do is to test the standard sample (control sample) that is supplied with the kit and ensure that the expected value (within the accepted variation) is obtained before testing any precious samples. This must be done using the procedure provided in the kit booklet without any modifications to the procedure. If there are still doubts about the results using the standard sample in the kit then send example results in the MegaCalc spread sheet to your product supplier (Megazyme or your local Megazyme distributor).
For samples with low concentrations of analyte the sample volume used in the kit assay can be increased to increase sensitivity. When doing this the water volume is adjusted to retain the same final assay volume. This is critical for the manual assay format because the assay volume and sample volume are used in the calculation of results.
The kit assay may work for biological fluids assuming that inositol is present above the limit of detection for the kit after any sample preparation (if required). Centrifugation of the samples and use of the supernatant directly in the kit assay (with appropriate dilution in distilled water) may be sufficient. However, if required a more stringent sample preparation method may be required and examples are provided at the following link:http://www.megazyme.com/docs/analytical-applications-downloads/biological_samples_111109.pdf?sfvrsn=2
The test kit has not been tested using biological fluids as samples because it is not marketed or registered as a medical device. This will therefore require your own validation.
The majority of the Megazyme test kits are developed to work in cuvettes using the manual assay format, however the assay can be converted for use in a 96-well microplate format. To do this the assay volumes for the manual cuvette format are reduced by 10-fold. The calculation of results for the manual assay format uses a 1 cm path-length, however the path-length in the microplate is not 1 cm and therefore the MegaCalc spreadsheet or the calculation provided in the kit booklet for the manual format cannot be used for the micropalate format unless the microplate reader being used can.
There a 3 main methods for calculation of results using the microplate format:
The volume/weight of sample and total volume of the extract can be modified to suit the sample. This will ultimately be dictated by the amount of analyte of interest in the sample and may require empirical determination. For low levels of analyte the sample:extract volume ratio can be increased (i.e. increase the sample and/or decrease the total extraction volume).
Alternatively, for samples with low concentrations of analyte, a larger sample volume can be added to the kit assay. When altering the sample volume adjust the distilled water volume added to the assay accordingly so that the total assay volume is not altered.
The test kit is extremely accurate – at Megazyme the quality control criteria for accuracy and repeatability is to be within 2% of the expected value using pure analytes.
However, the level of accuracy is obviously analyst and sample dependent.
Yes. Samples with the lower concentrations of analyte will generate a lower absorbance change. For samples with low concentrations of analyte, a larger sample volume can be used in the assay to increase the absorbance change and thereby increase sensitivity of the assay. When doing this the increased volume of the sample should be subtracted from the distilled water volume that is added to the assay so that the total assay volume is unaltered. The increase sample volume should also be accounted for when calculating final results.
No. The 0.1 change of absorbance is only a recommendation. The lowest acceptable change in absorbance can is dictated by the analyst and equipment (i.e. pipettes and spectrophotometer) and therefore can be can be determined by the user. With accurate pipetting, absorbance changes as low as 0.02 can be used accurately.
If a change in absorbance above 0.1 is required but cannot be achieved due to low concentrations of analyte in a sample, this can be overcome by using a larger sample volume in the assay to increase the absorbance change and thereby increase sensitivity of the assay. When doing this the increased volume of the sample should be subtracted from the distilled water volume that is added to the assay so that the total assay volume is unaltered. The increase sample volume should also be accounted for when calculating final results.
丙酮酸激酶（兔肌）
英文名：Pyruvate kinase (rabbit muscle)
货号：E-PKRM
规格：5,000 Units at 37°C
High purity pyruvate kinase (rabbit muscle) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 2.7.1.40
CAS: 9001-59-6
ATP:pyruvate 2-O-phosphotransferase
From rabbit muscle.
In 3.2 M ammonium sulphate.
Supplied at ~ 2,500 U/mL.
Specific activity: 233 U/mg protein at pH 7.2 and 37oC.
Stability: > 2 years 4oC.
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α-葡萄糖苷酶（嗜热脂肪芽孢杆菌）（重组）
英文名：α-Glucosidase (Bacillus stearothermophilus) (Recombinant)
货号：E-TSAGS
规格：3000 Units at 40°C /6000 Units at 60°C
Alpha葡[萄]糖苷酶[嗜热脂肪芽孢杆菌]
EC 3.2.1.20
CAZY Family: GH13
Recombinant from Bacillus stearothermophilus. In 3.2 M ammonium sulphate.
Specific activity: ~ 280 U/mg (60oC, pH 6.5 on p-nitrophenyl-α-D-glucopyranoside); ~ 135 U/mg (40oC, pH 6.5 on p-nitrophenyl-α-D-glucopyranoside).
Action on other substrates: Blocked p-nitrophenol maltoheptaoside < 0.0001 %
Stability: > 4 years at 4oC.
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1,4-β-D-Cellopentaitol (borohydride reduced cellopentaose)
英文名：1,4-β-D-Cellopentaitol (borohydride reduced cellopentaose)
货号：O-CPERD
规格：30 mg
CAS: 61473-65-2
Molecular Formula: C30H54O26
Molecular Weight: 830.7
Purity: > 95%
High purity 1,4-β-D-Cellopentaitol (borohydride reduced cellopentaose) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
Pentasaccharide from hydrolysis of cellulose and borohydride reduced.
Store at room temperature.
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Beta葡聚糖[MW Standard]
英文名：?-Glucan MW Standard 6x500mg
货号：P-MWBGS
规格：6 X 500 mg
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1，3-?-D-葡聚糖内切酶检测底物
英文名：AZCL-Curdlan 3g
货号：I-AZCUR
规格：3g
1,3-?-D-葡聚糖内切酶检测底物
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a-L-阿拉伯呋喃糖酶[杆菌芽胞]
英文名：α-L-Arabinofuranosidase (Clostridium thermocellum)
货号：E-ABFCT
规格：500 Units at 40°C
High purity recombinant alpha-L-Arabinofuranosidase (Clostridium thermocellum) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 3.2.1.55
CAZy family: GH51
Recombinant. From Clostridium thermocellum.
In 3.2 M ammonium sulphate.
Specific activity: 58 U/mg protein on p-nitrophenyl-α-L-arabinofuranoside at pH 5.5 and 40oC (155 U/mg at pH 5.5 and 60oC).
Stable at 4oC for ~ 4 years.
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Beta葡聚糖[混联]检测试剂盒
英文名：β-Glucan Assay Kit (Mixed Linkage)
货号：K-BGLU
规格：100 assays per kit
分析物意义： 大麦和燕麦的主要细胞壁多糖
Megazyme检测试剂盒优点：反应迅速、试剂稳定， 只有酶检测试剂盒可用。 AOAC方法 995.16; AACC 方法 32-23
AACC Method 32-23.01, AOAC Method 995.16, EBC Methods 3.11.1, 4.16.1 and 8.11.1, ICC Standard No. 166 and RACI standard method for the measurement of 1,3:1,4-ß-D-glucan in cereal grains, milling fractions, wort and beer. Recommended/Standard procedure of the Association of Official Analytical Chemists (AOAC), American Association of Cereal Chemists (AACC), Royal Australian Chemical Institute (RACI), European Brewing Convention (EBC), and International Association for Cereal Science and Technology (ICC). Content:100 assays per kit
Colourimetric method for the determination of β-Glucan in
cereal grains, feed, foodstuffs, beverages and other materials
Principle:
(lichenase)
(1) β-Glucan + H2O → β-gluco-oligosaccharides
(β-glucosidase)
(2) β-Gluco-oligosaccharides + H2O → D-glucose
(glucose oxidase)
(3) D-Glucose + H2O + O2 → D-gluconate + H2O2
(peroxidase)
(4) 2H2O2 + p-hydroxybenzoic acid + 4-aminoantipyrine →
quinoneimine + 4H2O
Kit size: 100 assays
Method: Spectrophotometric at 510 nm
Total assay time: ~ 100 min
Detection limit: 0.5-100% of sample weight
Application examples:
Oats, barley, malt, wort, beer, food and other materials
Method recognition:
AOAC (Method 995.16), AACC (Method 32-23.01), EBC (Methods
3.10.1, 4.16.1 and 8.13.1), ICC (Standard No. 166), RACI (Standard
Method) and CODEX (Type II Method)
Advantages
The pH of the assay solution after the sample is added should be the same as that of the assay buffer that is supplied with the kit.
Low sample volumes (e.g. 0.1 mL) are not likely to affect the pH of the assay solution and therefore may not require pH adjustment.
Samples above 0.1 mL are more likely to affect the pH of the assay solution and therefore the pH of these samples should be adjusted as described in the data booklet, prior to addition to the assay.
If you suspect that the Megazyme test kit is not performing as expected such that expected results are not obtained please do the following:
The MW’s were determined by Multiangle laser light scattering technique.
Barley beta-glucan lot 30108 would contain about 3-4% arabinoxylan (this was produced in 1993). Material supplied post 1995 contains < 0.5% arabinoxylan. Carob galactomannan is quite pure (> 96%).
The content of 1,3 bonds in barley beta-glucan is about 32% (from literature). We would not expect this to change much (if at all) over different batches.
The substrates are enzymically treated to yield the required viscosity (20 ~ 30 cSt). Modification of the viscosity of beta-glucan is required for IOB viscometric malt beta-glucanase test (which works well).
For glucanase assay we recommend the medium viscosity beta-glucan. We now offer low, medium and high viscosity wheat arabinoxylans, and we think that the low viscosity material will be best (easiest) to use in the reducing-sugar assay.
黄递酶[大肠杆菌]
英文名：Diaphorase (E. coli)
货号：E-DIAEC
规格：1000 Units
High purity Diaphorase (E. coli) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 1.8.1.4
From E. coli.
In 3.2 M ammonium sulphate.
Specific activity: 69 U/mg (25oC, pH 9.0).
Stable at 4oC for > 2 years.
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Alpha葡[萄]糖苷酶[嗜热脂肪芽孢杆菌]
英文名：α-Glucosidase (Bacillus stearothermophilus)
货号：E-TSAGL
规格：1500 Units
High purity alpha-Glucosidase (B. stearothermophilus) for use in research, biochemical enzyme assays and in vitrodiagnostic analysis.
EC 3.2.1.20
CAZy Family: GH13
From B. stearothermophilus.
In 3.2 M ammonium sulphate.
Specific activity: > 80 U/mg (40oC, pH 6.5, p-nitrophenyl α-D-glucoside).
Stable at 4oC for > 4 years.
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膳食纤维控粉总量检测试剂盒
英文名：Total Dietary Fibre Control Flours Kit
货号：K-TDFC
规格：Sufficient for 6 Controls
膳食纤维控粉总量检测试剂盒
For use with the Total Dietary Fibre Assay Kit.
Contains barley ß-glucan, high amylose maize starch, wheat starch, casein, pectin and larch galactan. Wheat arabinoxylan is available on request. Content: Sufficient for 10 assays
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木聚糖酶检测底物(1000)
英文名：Xylazyme (100mg) – 1000 Tablets
货号：T-XYZ-1000T
规格：1000 Tablets
High purity dyed and crosslinked Xylazyme (100 mg tablets) for the measurement of enzyme activity, for research, biochemical enzyme assays and in vitro diagnostic analysis.
For the assay of endo-1,4-ß-D-xylanase. Containing AZCL-arabinoxylan (wheat). This substrate is the same as Xylazyme AX except for the larger tablet size (i.e. 100 mg cf. 60 mg) and slightly different assay format.
木聚糖酶检测底物
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CAPS缓冲液
英文名：CAPS Buffer salt 200 grams
货号：B-CAPS200
规格：200g
CAPS缓冲液
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外切-1，3 – β-D-葡聚糖酶+β葡萄糖苷
英文名：exo-1，3-β-D-Glucanase + β-Glucosidase
货号：E-EXBGOS
规格：300 Units exo-13-β-glucanase/
High purity exo-1,3-β-D-Glucanase Trichoderma sp. + β-Glucosidase (Aspergillus niger) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 3.2.1.58 (exo-1,3-β-Glucanase)
CAZy Family: GH55
CAS: 9073-49-8
glucan 1,3-beta-glucosidase; 3-beta-D-glucan glucohydrolase
EC 3.2.1.21 (β-Glucosidase)
CAZy Family: GH3
CAS: 9001-22-3
beta-glucosidase
exo-1,3-β-D-Glucanase: Recombinant. From Trichoderma sp.
β-Glucosidase: From Aspergillus niger.
In 3.2 M ammonium sulphate.
Activity/Concentration: exo-1,3-β-Glucanase (100 U/mL) / β-Glucosidase (20 U/mL).
Stability: > 2 years at 4oC.
DESCRIPTION
exo-1,3-β-D-Glucanase + β-Glucosidase
EC 3.2.1.58 (exo-1,3-β-D-Glucanase)
CAZy Family: GH55
CAS: 9073-49-8
EC 3.2.1.21 (β-Glucosidase)
CAZY Family: GH3
CAS: 9001-22-3
Synonyms
(exo-1,3-β-D-Glucanase): glucan 1,3-beta-glucosidase; 3-beta-D-glucan glucohydrolase (β-Glucosidase): beta-glucosidase
Form:
In 3.2 M ammonium sulphate.
Stability:
> 2 years at 4oC.
Activity:
exo-1,3-β-Glucanase: 100 U/mL
β-Glucosidase: 20 U/mL
Unit definition:
One Unit of exo-1,3-β-glucanase activity is defined as the amount of enzyme required to release one μmole of glucose reducing-sugar equivalents per minute from laminarin (10 mg/mL) in sodium acetate buffer (100 mM), pH 4.0 at 40oC.
One Unit of β-glucosidase activity is defined as the amount of enzyme required to release one μmole of p-nitrophenol per minute from 4-nitrophenyl-β-D-glucpyranoside in sodium acetate buffer (100 mM), pH 4.0 at 40oC.
Specificity:
exo-1,3-β-glucanase: Successive hydrolysis of β-D-glucose units from the non-reducing ends of (1,3)-β-D-glucans, releasing α-glucose.
β-glucosidase: Hydrolysis of terminal, non-reducing β-D-glucosyl residues with release of β-D-glucose.
Applications:
For use in the determination of (1,3)(1,4) β-glucan.
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菊粉外切酶[黑曲霉]
英文名：exo-Inulinase (Aspergillus niger) (Recombinant)
货号：E-EXOIAN
规格：5000 Units at 40°C
High purity recombinant exo-Inulinase (Aspergillus niger) for use in research, biochemical enzyme assays and in vitrodiagnostic analysis.
EC 3.2.1.80
CAZy Family: GH32
CAS: 37288-56-5
fructan beta-fructosidase; beta-D-fructan fructohydrolase
(Also assigned to EC 3.2.1.26)
CAZy Family: GH32
CAS: 9001-57-4
beta-fructofuranosidase; beta-D-fructofuranoside fructohydrolase
Recombinant. From Aspergillus niger.
In 3.2 M ammonium sulphate.
Specific activity: ~ 2000 U/mg (60oC, pH 4.5 on kestose); ~1000 U/mg (40oC, pH 4.5 on kestose).
Stability: > 4 years at 4oC.
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Beta葡聚糖[燕麦；高黏度]
英文名：Beta-Glucan (Oat; High Viscosity) 5g
货号：P-BGOH
规格：5 grams
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淀粉葡萄糖苷酶[根霉]
英文名：Amyloglucosidase (Rhizopus sp.)
货号：E-AMGPU
规格：5000u
High purity Amyloglucosidase (Rhizopus sp.) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 3.2.1.3
CAZy Family: GH15
From Rhizopus sp. Ultra high purity. Electrophoretically homogeneous. Freeze-dried powder.
Specific activity: approx. 35 U/mg (40oC, pH 4.5, soluble starch as substrate).
Stable for > 4 years at -20oC.
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Beta葡[萄]糖苷酶[农杆菌]
英文名：Beta-Glucosidase – 600U.
货号：E-BGOSAG
规格：600u
High purity beta-Glucosidase (Agrobacterium sp.) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 3.2.1.21
CAZy Family: GH1
From Agrobacterium sp.
In 3.2 M ammonium sulphate. Stabilised with BSA. Electrophoretically homogeneous (before BSA addition).
Specific activity: 211 U/mg (40oC, pH 4.0, p-nitrophenyl β-glucoside).
Stable at 4oC for > 4 years.
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山梨醇/木糖醇检测试剂盒
英文名：D-Sorbitol/Xylitol Assay Kit
货号：K-SORB
规格：58 assays (manual) / 580 assays (microplate)
分析物意义： 食品中常见的增甜剂有阿斯巴甜、D-甘露醇、D-山梨醇和木糖醇
Megazyme检测试剂盒优点：K-SORB- 提供的硫辛安脱氢酶是稳定的悬浮液而不是可溶性粉末，从而减少酶的浪费
The D-Sorbitol/Xylitol test kit is suitable for the measurement and analysis of D-sorbitol and/or xylitol in food products.
Suitable for manual, auto-analyser and microplate formats.
Colourimetric method for the determination of D-Sorbitol and
Xylitol in foodstuffs and wine
Principle:
(sorbitol dehydrogenase)
(1) D-Sorbitol + NAD+ ↔ D-fructose + NADH + H+
(sorbitol dehydrogenase)
(2) Xylitol + NAD+ ↔ D-xylulose + NADH + H+
(diaphorase)
(3) INT + NADH + H+ → NAD+ + INT-formazan
Kit size: 58 assays (manual) / 580 (microplate)
/ 700 (auto-analyser)
Method: Spectrophotometric at 492 nm
Reaction time: ~ 15 min
Detection limit: 0.20 mg/L
Application examples:
Diabetic foods (e.g. honey, jam and chocolate), dietetic foods,
chewing gum, candies, fruit juice (e.g. apple juice), ice-cream, sweets,
bakery products (e.g. desserts), marzipan, paper (and cardboard),
cosmetics, pharmaceuticals and other materials (e.g. biological cultures,
samples, etc.)
Method recognition:
Methods based on this principle have been accepted by IFU and AIJN
Advantages
Q1. Should the pH of the sample be adjusted even for samples in acidic media?
The pH of the assay solution after the sample is added should be the same as that of the assay buffer that is supplied with the kit.
Low sample volumes (e.g. 0.1 mL) are not likely to affect the pH of the assay solution and therefore may not require pH adjustment.
Samples above 0.1 mL are more likely to affect the pH of the assay solution and therefore the pH of these samples should be adjusted as described in the data booklet, prior to addition to the assay.
If you suspect that the Megazyme test kit is not performing as expected such that expected results are not obtained please do the following:
Ensure that you have tested the standard sample that is supplied with the Megazyme test kit.
Send the results of the kit standard, blank samples and the results obtained for your sample, in the relevant MegaCalc spreadsheet (if available) to Megazyme (cs@megazyme.com). Where available the relevant MegaCalc spreadsheet can be downloaded from where the product appears on the Megazyme website.
State the kit lot number being used (this is found on the outside of the kit box).
State which assay format was used (refer to the relevant page in the kit booklet if necessary).
State exact details of any modifications to the standard procedure that is provided by Megazyme.
State the sample type and describe the sample preparation steps if applicable.
Deproteinisation
Deproteinisation with perchloric acid:
1 M Perchloric acid: [Sigma Cat No. 244252; MW 100.46; d = 1.664 (g/mL); 16.56 M]
Add 6 mL perchloric acid to 94 mL of distilled water and mix thoroughly.
1 M potassium hydroxide: (Sigma Cat No. 60369; MW 56.11; 86% assay)
Add 6.5 g of potassium hydroxide pellets to approximately 80 mL of distilled water and stir to dissolve. Make to 100 mL with distilled water.
Deproteinise samples containing protein by adding an equal volume of ice-cold 1 M perchloric acid with mixing. Filter or centrifuge at 1,500 g for 10 min and adjust the pH of the supernatant to between 7 and 8 with 1 M KOH. Use the supernatant in the assay after appropriate dilution. Alternatively, use trichloroacetic acid.
Deproteinisation with trichloroacetic acid:
50% (w/v) trichloroacetic acid (approx. 3 M): (Sigma Cat No. 33731; MW 163.39)
Add 50 g of trichloroacetic acid to approximately 80 mL of distilled water and stir to dissolve. Make to 100 mL with distilled water.
Where the amount of analyte in a liquid sample is unknown, it is recommended that a range of sample dilutions are prepared with the aim of obtaining an absorbance change in the assay that is within the linear range.
Where solid samples are analysed, the weight of sample per volume of water used for sample extraction/preparation can be altered to suit, as can the dilution of the extracted sample prior to the addition of the assay, as per liquid samples.
The final pH of the kit assay after the sample is added should not change from what it should be (as stated in the kit for the assay buffer). If it does change then the sample will require pH adjustment. In most cases the sample volume being used is low relative to the final assay volume and in this case the pH of the kit assay is unlikely to be affected.
For users who are not familiar with how to use the Megazyme tests kits then it is recommended that they follow this example, e.g. D-Fructose/D-Glucose Assay kit K-FRUGL (http://secure.megazyme.com/D-Fructose-D-Glucose-Assay-Kit):
1. The kit components are listed on pages 2-3 of the kit booklet.
2. Prepare the kit reagents as described on page 3.
3. For separate measurements of glucose and fructose follow procedure A on page 4.
4. Pipette the volumes listed for water, sample, solution 1 and solution 2 into 3 mL, 1 cm pathlength cuvettes. Duplicate sample assays and duplicate blanks are recommended. Mix the contents of each cuvette by inversion (seal the cuvette using parafilm or a plastic cuvette cap – do not use a finger) then after ~3 min record the first absorbance reading of each cuvette at 340 nm (this is reading A1).
5. Then add suspension 3 and mix the contents of each cuvette by inversion. Incubate for 5 minutes then record the absorbance reading of each cuvette at 340 nm (this is reading A2). NB. It is essential that the reaction is compete. To assess this, record the absorbances at ~ 2 minute intervals and until the absorbance plateaus. A stable absorbance indicates that the reaction is complete. If the absorbance continues to increase then continue to record absorbances until it plateaus and only then record absorbance reading A2.
6. Then add suspension 4 and mix the contents of each cuvette by inversion. Incubate for 5 minutes then take absorbance reading of each cuvette at 340 nm (this is reading A3). NB. As above, assess that the reaction has completed by take subsequent readings at ~2 min intervals.
7. For simple, automated results analysis, input the absorbance readings (A1, A2, A3) for samples and blanks into the K-FRUGL MegaCalc.
To ensure that the assay is working, and being performed correctly it is recommend that the test is performed using the standard sample that is provided with the kit and to obtain the expected values before proceeding to test real samples.
It is recommend that new users also watch this video which highlights how to perform the assays.
Many of the other Megazyme test kits follow a similar format.
If there are any concerns with any kit components, the first thing to do is to test the standard sample (control sample) that is supplied with the kit and ensure that the expected value (within the accepted variation) is obtained before testing any precious samples. This must be done using the procedure provided in the kit booklet without any modifications to the procedure. If there are still doubts about the results using the standard sample in the kit then send example results in the MegaCalc spread sheet to your product supplier (Megazyme or your local Megazyme distributor).
The kit assay may work for biological fluids assuming that inositol is present above the limit of detection for the kit after any sample preparation (if required). Centrifugation of the samples and use of the supernatant directly in the kit assay (with appropriate dilution in distilled water) may be sufficient. However, if required a more stringent sample preparation method may be required and examples are provided at the following link:http://www.megazyme.com/docs/analytical-applications-downloads/biological_samples_111109.pdf?sfvrsn=2
The test kit has not been tested using biological fluids as samples because it is not marketed or registered as a medical device. This will therefore require your own validation.
The majority of the Megazyme test kits are developed to work in cuvettes using the manual assay format, however the assay can be converted for use in a 96-well microplate format. To do this the assay volumes for the manual cuvette format are reduced by 10-fold. The calculation of results for the manual assay format uses a 1 cm path-length, however the path-length in the microplate is not 1 cm and therefore the MegaCalc spreadsheet or the calculation provided in the kit booklet for the manual format cannot be used for the micropalate format unless the microplate reader being used can.
There a 3 main methods for calculation of results using the microplate format:
For samples with low concentrations of analyte the sample volume used in the kit assay can be increased to increase sensitivity. When doing this the water volume is adjusted to retain the same final assay volume. This is critical for the manual assay format because the assay volume and sample volume are used in the calculation of results.
The test kit is extremely accurate – at Megazyme the quality control criteria for accuracy and repeatability is to be within 2% of the expected value using pure analytes.
However, the level of accuracy is obviously analyst and sample dependent.
Yes, instead of adding 2 μL of enzyme suspension an alternative is to dilute the enzyme and add a larger volume to the microplate assay.
Dilute the assay buffer 10-fold with distilled water and use this as the diluent to dilute an aliquot of the enzyme suspension also by 10-fold. Instead of 2 μL, use 20 μL of the diluted enzyme in the microplate assay.
Some samples can react with the INT in the assay and cause a non-enzymatic creep reaction.
The 3rd worksheet in the MegaCalc is used to account for any creep reaction in your results.
No. The 0.1 change of absorbance is only a recommendation. The lowest acceptable change in absorbance can is dictated by the analyst and equipment (i.e. pipettes and spectrophotometer) and therefore can be can be determined by the user. With accurate pipetting, absorbance changes as low as 0.02 can be used accurately.
If a change in absorbance above 0.1 is required but cannot be achieved due to low concentrations of analyte in a sample, this can be overcome by using a larger sample volume in the assay to increase the absorbance change and thereby increase sensitivity of the assay. When doing this the increased volume of the sample should be subtracted from the distilled water volume that is added to the assay so that the total assay volume is unaltered. The increase sample volume should also be accounted for when calculating final results.
Yes. Samples with the lower concentrations of analyte will generate a lower absorbance change. For samples with low concentrations of analyte, a larger sample volume can be used in the assay to increase the absorbance change and thereby increase sensitivity of the assay. When doing this the increased volume of the sample should be subtracted from the distilled water volume that is added to the assay so that the total assay volume is unaltered. The increase sample volume should also be accounted for when calculating final results.
Azo-果聚糖+外切菊粉酶2克
英文名：Azo-Fructan+exo-Inulinanase 2g
货号：S-AZFRXOI
规格：2 grams + 4000 Units of pure exo-inulinase
A substrate for the specific assay of endo-inulinase.
内切型菊粉酶特殊检测底物
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1，4-b-D-半乳糖内切酶[芽孢杆菌]
英文名：endo-1，4-β-Galactanase (Cellvibrio japonicus)
货号：E-GALCJ
规格：1500 Units
High purity recombinant endo-1,4-beta-Galactanase (Cellvibrio japonicus) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 3.2.1.89
CAZy Family: GH53
Recombinant. Native full-length Gal53 from Cellvibrio japonicus.
In 3.2 M ammonium sulphate.
Specific activity: ~ 100 U/mg (40oC, pH 8.0 on potato galactan).
Stability: > 2 years at 4oC.
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鼠李聚糖半乳糖醛酸水解酶和裂解酶检测底物
英文名：AZCL-Rhamnogalacturonan I – 2grams
货号：I-AZRHI
规格：2g
鼠李聚糖半乳糖醛酸水解酶和裂解酶检测底物
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果胶酸裂合酶M1[曲霉菌]
英文名：Pectate Lyase (Aspergillus sp.) Pectate Lyase (Aspergillus sp.)
货号：E-PCLYAN2
规格：7500
果胶酸裂合酶M1[曲霉菌]
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茯苓聚糖[1，3-b-D-葡聚糖]
英文名：Pachyman (1，3-?-D-Glucan) 5g
货号：P-PACHY
规格：5 grams
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6-磷酸葡糖酸脱氢酶[大肠杆菌]
英文名：6-Phosphogluconate dehydrogenase (E. coli)
货号：E-PGDHEC
规格：150 Units
High purity recombinant 6-Phosphogluconate dehydrogenase (E. coli) for use in research, biochemical enzyme assays and in vitro diagnostic analysis.
EC 1.1.1.44
Recombinant from E. coli.
In 3.2 M ammonium sulphate.
Specific activity: ~30 U/mg (25oC, pH 7.6).
Stable at 4oC for > 2 years.
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