Alpha-amylase determination with the Reflotron reagent carrier system: use of whole blood, plasma, and serum, and effect of isoenzymes.
In the Reflotron Amylase dry-reagent carrier system (Boehringer Mannheim GmbH) a new substrate is used for determining total amylase (EC 3.2.1.1) activity:indolyl-alpha-D-maltoheptaoside. The procedure shows low imprecision (median CV less than 3.2%), and results for sera, plasma, and capillary and venous blood (y) correlate well with those of a conventional alpha-amylase method involving p-nitrophenyl (PNP)-maltoheptaoside substrate (x) (for 209 blood samples: y = 0.981x + 9.7; r = 0.994). Correlation was also excellent with a method involving maltotetraose as substrate (r = 0.987). Attachment of an indoxyl residue rather than a PNP group to the maltoheptaoside did not affect the substrate response to pancreatic or salivary isoenzyme activity. Therefore, the relative proportion of these isoenzymes did not affect the correlation between the Reflotron Amylase reagent carrier and the alpha-amylase PNP-maltoheptaoside method. With a reaction time of less than 3 min, this system is especially suitable for amylase determination in situations where a prompt result is required.
Division of Clinical Chemistry, Institute of Medical and Veterinary Science, Adelaide, S.A., Australia.
R
R
Bais
J
J
Badenoch
P M
PM
Bayer
Y
Y
Foo
H
H
Keller
P U
PU
Koller
R
R
Leinberger
G
G
Weidemann
S B
SB
Rosalki
D006801:Humans; D007527:Isoenzymes / Q000097:blood*; D010179:Pancreas / Q000201:enzymology; D010783:Photometry / Q000379:methods; D010949:Plasma / Q000201:enzymology; D012463:Saliva / Q000201:enzymology; D013379:Substrate Specificity; D000516:alpha-Amylases / Q000097:blood*
D007527:Isoenzymes; D000516:alpha-Amylases