The main analytical pitfalls in insulin measurement in serum are related to (a) hemolysis, (b) circulating anti-insulin autoantibodies, and, for the past few years, (c) the reactivity (or lack of reactivity) of rapid- or long-acting pharmacological ins...More
This protocol may be used to measure insulin in plasma or serum sample where hemolysis may occur. To do so, blood samples are collected in tubes containing EDTA. The samples are centrifuged at 1600 g for 20 minutes. Plasmas are collected and kept at -20°C until assay.
Allow to collect 2.5 mL of sample and process one kit.
Thaw inhibitor cocktail #D05011 and add 10 µL for 1mL of plasma (or 5 µL for 500 µL, 2 µL for 200 µLetc..).
Add 10µL of inhibitor cocktail #D05011 in the reconstituted Insulin Standard ( vial #A06105 reconstituted with 1mL UltraPure water), and 10µL of inhibitor cocktail in the reconstituted Insulin QC ( vial #A10105 reconstituted with 1mL UltraPure water).
Inhibitor Buffer will be used to process additional dilutions : serial dilutions of the Insulin Standard, dilutions of the samples. How to prepare Inhibitor Buffer : prepare EIA Buffer by diluting the vial #A07000 with 50 mL UltraPure water; pipet 25 mL of this EIA Buffer and add 250 µL of the inhibitor cocktail #D05011. Mix thoroughly by gentle inversion.
Chevenne D., Letailleur A., Trivin F., and Porquet D.,Effect of Hemolysis on the Concentration of Insulin in Serum Determined by RIA and IRMA, Clin. Chem., 44: 354 - 356, Feb 1998
Sapin R., Insulin Immunoassays: Fast Approaching 50 Years of Existence and