英文名：β-Glucanase Assay Kit (Malt and Microbial)
规格：100 assays per kit
β-Glucanase (Malt and Microbial) Assay Kit is suitable for the measurement and analysis of malt and bacterial β-glucanase and endo-1,4-β-glucanase.
Colourimetric method for the determination of β-Glucanase
in malt, foodstuffs and fermentation products
(1) Azo-Barley β-glucan (polymer) → Azo-barley β-glucan
(2) Add alcohol; centrifuge to remove polymeric Azo-barley
(3) Measure the absorbance of the supernatant solution
Kit size: 100 assays
Method: Spectrophotometric at 590 nm
Reaction time: ~ 30 min
Detection limit: 100 U/kg of malt
Malt extracts, wort, beer and other materials
RACI (Standard Method)
- Very cost effective
- All reagents stable for > 2 years during use
- Only kit available
- Very specific
- Simple format
- Standard included
Q1. We have measured the molecular weight of beta-glucan originating from barley ordered from your company. Can you please tell us which method you have used for measuring molecular weight?
The MW’s were determined by Multiangle laser light scattering technique.
Q2. I have purchased barley beta-glucan (lot 30108) and carob galactomannan low viscosity (lot 30702) and would like to know what else there might be in these substrates.
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%).
Q3. Although not specified on the beta-glucan data sheet, is the ratio of 1-3 to 1-4 bonds measured? If so, what is the ratio and would you expect it to remain standardised over a number of different batches?
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.
Q4. Both substrates, barley beta-glucan and wheat arabinoxylan, are standardised to a specific viscosity, e.g. 23-24 cSt. Are the substrates adjusted to give this viscosity?
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).
Q5. 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.
Q6. 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:
- 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 ([email protected]). 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.
Q7. We want to set up reducing-sugar assays for beta-glucanase and xylanase from different fungal origins. There are three kinds in your catalogue – high viscosity, medium viscosity and low viscosity. Which do you recommend for the glucanase assay.
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.