Amylase measurement with 2-chloro-4-nitrophenyl maltotrioside as substrate.
The use of 2-chloro-4-nitrophenyl maltotrioside (CNP-G3) as substrate to measure amylase (EC 3.2.1.1) activity in serum directly without the use of auxiliary enzymes was evaluated at two centres. The method was precise (within-run C.V. < 2% and between-run C.V. < 3%), there was no lag phase, background absorbance was low and there were minimal effects of pH changes. When compared with a method which uses 4,6-ethylidene (G7)-p-nitrophenyl (G1)-alpha-D-maltoheptaoside (EPS-G7) as substrate, the CNP-G3 method had greater sensitivity and longer reagent stability (21 days compared with 2 days at 4 degrees C). The activity measured with the CNP-G3 method correlated well with methods using either EPS-G7 and maltotetraose as substrates.
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Department of Chemical Pathology, The Royal Free Hospital, London, UK.
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D000681:Amylases / Q000097:blood*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013379:Substrate Specificity; D014312:Trisaccharides / Q000378:metabolism*
D007202:Indicators and Reagents; D014312:Trisaccharides; C057413:2-chloro-4-nitrophenylmaltotrioside; D000681:Amylases