Elbin C S, Becks S, Lepp C A
Department of Research and Development, 810 S.D. Corporation, Westlake, OH 44145.
Clin Chem. 1993 Jan;39(1):112-8.
We describe a reagent for measuring alpha-amylase (EC 3.2.1.1) activity in serum with use of a thexyldimethylsilyl ether of p-nitrophenyl-alpha-D-maltoheptaoside (SB7) as substrate. This substrate differs from Genzyme's benzylidene-blocked p-nitrophenylmaltoheptaoside substrate (B-PNPG7). The reagent, optimized for the characteristics of the silyl-blocked substrate, contains 4-(2-hydroxyethyl)-1-piperazineethane sulfonate buffer at pH 7.3, alpha-glucosidase (maltase; EC 3.2.1.20), and glucoamylase (EC 3.2.1.3). Comparison with Ciba Corning Diagnostics Corp.'s, amylase reagent with B-PNPG7 as substrate (x) yielded a regression equation of y = 1.20x-2.7 (r = 0.9997). The linear range exceeded amylase concentrations > 2500 U/L and total precision (CV) was 2.3% at an amylase concentration of 112 U/L with the Ciba Corning 550 Express analyzer. Reconstituted reagent is stable for 30 days at 5 degrees C and 7 days at ambient (18-25 degrees C) temperatures.
我们描述了一种试剂，该试剂使用对硝基苯基-α-D-麦芽庚糖苷的叔丁基二甲基甲硅烷基醚（SB7）作为底物来测定血清中的α-淀粉酶（EC 3.2.1.1）活性。这种底物不同于Genzyme公司的亚苄基封闭的对硝基苯基麦芽庚糖苷底物（B-PNPG7）。针对甲硅烷基封闭底物的特性进行了优化的该试剂，含有pH 7.3的4-(2-羟乙基)-1-哌嗪乙烷磺酸盐缓冲液、α-葡萄糖苷酶（麦芽糖酶；EC 3.2.1.20）和葡糖淀粉酶（EC 3.2.1.3）。与以B-PNPG7作为底物的汽巴康宁诊断公司的淀粉酶试剂（x）进行比较，得到回归方程y = 1.20x - 2.7（r = 0.9997）。在使用汽巴康宁550 Express分析仪时，线性范围超过淀粉酶浓度>2500 U/L，在淀粉酶浓度为112 U/L时总精密度（CV）为2.3%。复溶后的试剂在5℃下稳定30天，在环境温度（18 - 25℃）下稳定7天。
