Shared Flashcard Set

Details

Final Practical
Amylase
11
Chemistry
Graduate
04/16/2013

Additional Chemistry Flashcards

 


 

Cards

Term
Perform the amylase method via a manual kit by Stanbio
Definition
Label 4 tubes and then zero spectrophotometer with DI water (405 nm), add Amylase reagent to each tube and incubate at 37 C for 3 minutes. Add appropriate sample to each tube one at a time and then read immediately. Read absorbance at 30 seconds intervals for 2 minutes. Determine the mean absorbance difference per minute, and multiply that by 4824 to get result in U/L.
Term
Identify interfering substances for amylase determination
Definition
Drugs and substances
Term
reference range for amylase serum
Definition
25-125 U/L
Term
reference range for amylase urine
Definition
1-17 U/hour
Term
principle of the amylase determination
Definition
The principle of this method is based on alpha-amylase enzyme which catalyzes the hydrolytic cleavage of starch and glycogen. The procedure is based on the Wallenfels modification which uses substrate p-Nitrophenyl-D-maltoheptaoside (PNPG7) with the terminal glucose blocked to reduce spontaneous degradation of the substrate by glucosidase and glycoamylase. Amylase hydrolyzes p-Nitrophenyl D-maltoheptaoside (PNPG7) to p-Nitrophenyl-maltotriose (PNPG3) and maltotetraose. Glucoamylase hydrolyzes PNPG3 to p-Nitrophenylglycoside (PNPG1) and glucose. Then PNPG1 is hydrolyzed by glucosidase to glucose and p-Nitrophenol, which produces a yellow color. The rate of increase in absorbance is measured at 405 nm and is proportional to the amylase activity in the sample.
Term
concentration of amylase using change in absorbance over time.
Definition
U/L = ∆Abs./min. x 4824
Term
State classic reference method for amylase activity
Definition
Wallenfels method
Term
Briefly describe the classic reference method for amylase activity
Definition
Wallenfrels method uses PNPG7 which is hydrolyzed by amylase in the specimen to PNPG3 and maltotetraose. PNPG3 is then is hydrolyzed by glucoamylase to PNPG1 and glucose. PNPG1 is hydrolyzed by glucosidase to glucose and p-Nitrophenol which produces a yellow color. The rate of increase in absorbance is proportional to the amylase activity in the sample.
Term
Briefly describe the analytical methods which may be used to determine amylase isoenzymes.
Definition
The analytic methods for determining amylase isoenzymes are (1) electrophoresis (2) ion-exchange chromatography (3) isoelectric focusing (4) selective inhibition of the S-AMY by a wheat germ inhibitor (5) immunoprecipitation by a monoclonal antibody and (6) immunoinhibition.
Term
List several sources of error for the assay of amylase activity.
Definition
The sources of error for the amylase assay are interfering drugs and substances.
Term
What is the diagnostic significance of elevated serum and urine amylase measurement?
Definition
The diagnostic significance of elevated serum and urine amylase is that amylase rised with 6 hours of pancreatitis.
Supporting users have an ad free experience!