Both reagents, Amylase HR #R-AMHR4 and Amylase (Ceralpha) #R-CAAR4 can be used to quantitatively assay cereal, fungal and bacterial alpha-amylases. Both are simple methods, which employ as a substrate, the defined oligosaccharide “non-reducing-end blocked p-nitrophenyl maltoheptaoside” (BPNPG7) in the presence of excess levels of enzymes: R-AMHR4 - thermostable a-glucosidase and R-CAAR4 - amyloglucosidase and yeast α-glucosidase mixture. Both substrates are used exactly the same way.


The major difference is the ability to use the Amylase HR Reagent at temperatures up to 60°C, and at pH values up to 7.0. Whereas the Amylase (Ceralpha) Reagent can be used only in the pH range of 5.0 to 6.0 and at, or below, 40°C, due to the pH and temperature sensitivities of the amyloglucosidase and α-glucosidase. This is of particular advantage when assaying for bacterial α-amylases.

Megazyme supplies 3 kits for the measurement of alpha-amylase:

K-CERA – containing  2 bottles of Amylase HR Reagent, concentrated buffer, concentrated stopping reagent and malt flour control

R-AMHR4 – containing 4 bottles of Amylase HR Reagent

R-CAAR4 – containing 4 bottles of Cereal Alpha-Amylase Reagent (Ceralpha)


The main component for the measurement of alpha-amylase is the reagent mixture, as buffer and stopping reagent can be prepared by the customer using commonly available chemicals.

Product Page (R-CAAR4)

Product Page (R-AMHR4)

Product Page (K-CERA)