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:

1. Ensure that you have tested the standard sample that is supplied with the Megazyme test kit.
2. 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.
3. State the kit lot number being used (this is found on the outside of the kit box).
4. State which assay format was used (refer to the relevant page in the kit booklet if necessary).
5. State exact details of any modifications to the standard procedure that is provided by Megazyme.
6. State the sample type and describe the sample preparation steps if applicable.

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.