Principles of the Reaction
The substrate 2-chloro-p-nitrophenyl-D-maltotrioside [CNPG3] is hydrolyzed by α-amylase to release 2-chloro-p-nitrophenol [CNP] which is monitored spectrophotometrically at 405 nm. The hydrolysis products also include 2-chloro-4-nitrophenyl-D-maltoside [CNPG2], maltotriose [G3] and glucose [G]. The rate of formation of the 2-chloro-p-nitrophenol is directly proportional to the concentration of α-amylase activity in the sample.
10 CNPG3 -> 9 CNP + 1 CNPG2 + 9 G3 + 1G
Most applications of the procedure have been found to be linear to at least 1,500 U/L amylase.
A reference range for α-amylase in serum in adults measured at 37° C by a similar kinetic method is reported to be 25-125 U/L.
Special Performance Characteristics
- The Synermed® Amylase methodology was correlated to a commercially available amylase method. The calculated linear regression on 44 serum samples ranging from approximately 9 to 572 U/L with Synermed results on the Y-axis is: Y = 1.02X + 0.14 U/L with a correlation coefficient of 0.999
- The sensitivity of the procedure is such that an absorbance change per minute of 0.001 will detect as little as 6 U/L amylase.
- The within run precision of the method as applied to an automated analyzer was determined by assaying 30 samples of quality control materials at two levels of amylase concentration yielding the following results:
- The run to run reproducibility of the method as applied to an automated analyzer was determined from the values obtained by 5 replicate analyses of quality control material assayed over a 21 batch period. The following results were obtained:
Product Packaging and Storage
||Package Volume (mL)
||2 x 100 mL