β-淀粉酶检测试剂盒

产品货号：K-BETA3

品牌：Megazyme

产品品名：β-淀粉酶检测试剂盒

英文品名：Betamyl-3; β-amylase Assay Kit

规格型号： 100/200 assays per kit 

For the specific measurement of beta-amylase in malt flour.

上海西宝生物专业提供β-淀粉酶检测试剂盒，原装进口，
咨询热线：400-021-8151

β-Amylase plays a central role in the c o mplete degradation of starch to metabolisable or fermentable sugars during the germination or malting of cereal grains. It also finds considerable application, together with starch debranching enzymes, in the production of high maltose syrups.β-Amylase is usually measured using non-specific reducing sugar assays with starch as substrate. In some methods, the α-amylase is first inactivated by treatment at low pH. A major advance in the assay of β-amylase was introduced by Mathewson and Seabourn1 who found that the Calbiochem Pantrak serum α-amylase reagent could be used to measure β-amylase in the presence of cereal α-amylase. The reagent (Pantrak) consists of a mixture of p-nitrophenyl-α-D-maltopentaoside (PNPG5) and p-nitrophenyl-α-D-maltohexaoside (PNPG6). These substrates are rapidly hydrolysed by β-amylase, but are only slowly cleaved by cereal α-amylase, which requires a longer stretch of α-1,4-linked D-glucosyl residues to satisfy the substrate sub-site binding requirements.Subsequently, Megazyme offered a product, Betamyl? (β-Amylase Assay Reagent) that c o mprised just PNPG5 and α-glucosidase2, which gave greater specificity. This reagent is now superceded by the Megazyme Betamyl-3?, β-Amylase assay reagent, which is more specific and considerably more stable than the Betamyl reagent.

The Megazyme Betamyl-3, β-amylase test reagent employs high purity β-glucosidase and p-nitrophenyl-β-D-maltotrioside (PNPβ-G3). The level of β-glucosidase used ensures maximum sensitivity of the assay. On hydrolysis of PNPβ-G3 to maltose and p-nitrophenyl-β-Dglucoseby β-amylase, the p-nitrophenyl-β-D-glucose is immediately cleaved to D-glucose and free p-nitrophenol by the β-glucosidase present in the substrate mixture (Scheme 1). Thus, the rate of release of p-nitrophenol relates directly to the rate of release of maltose by β-amylase. The reaction is stopped, and the phenolate colour is developed, on addition of a high pH Trizma base solution. The PNPβ-G3 plus β-glucosidase mixture contains stabilisers which significantly increase its stability. The blank absorbance value of the Betamyl-3 substrate solution, when stored at 4 or 20°C, increases much more slowly than similar increases for Betamyl. reagent

Kits suitable for performing 100 assays are available from Megazyme.The kits contain the full assay method plus:

Bottle 1: (x2) Each vial contains p-nitrophenyl-β-D-maltotrioside (PNPβ-G3) plus β-glucosidase (50 U) and stabilisers.Stable for > 4 years at -20°C.
Bottle 2: Tris/HCl buffer (25 mL, 1 M, pH 8.0) plus disodium EDTA (20 mM) and sodium azide (0.02 % w/v). Stable for approx. 4 years at 4°C.
Bottle 3: MES buffer (48 mL, 1 M, pH 6.2) plus disodium EDTA (20 mM), BSA 10 mg/mL and sodium azide (0.20 % w/v). Stable for approx. 4 years at 4°C.
Bottle 4: Cysteine hydrochloride (16 g). Stable for > 2 years at room temperature.
Bottle 5: Malt flour of standardised β-amylase activity (as specified on bottle label). Stable for > 4 years at room temperature.