Lactate and Pyruvate Determination in 50 μ1 Whole Blood

Abstract

Capillary blood collected in a disposable 50 μ1 glass capillary pipette is deproteinized with perchloric acid. Lactate and pyruvate are determined on the same supernate. For lactate determination alone a 20 μ1 pipette is used. The final volume for the pyruvate determination is 104 μ1, for the lactate determination 140 μ1. The methods are based on the LDH-catalyzed reactions utilizing NAD⁺ respectively NADH. The precision of the lactate determination was improved by measuring at 350 nm rather than the absorption maximum of NADH at 340 nm, by using arsenite as buffer rather than the commonly used glycine buffer, and by reducing the commonly used hydrazine concentration to one-sixtieth.

Key Words:

• Capillary blood analysis
• laboratory techniques
• lactate analysis
• micro method
• newborns
• normal values
• pyruvate analysis