Automated micro method for enzymatic L(+) and D(-) lactic acid determinations in biological fluids containing cellular extracts.

Automated micro methods for the rapid assay of l(+) and d(?) lactic acid in rumen fluid and other biological extracts were developed using an Auto-samplerpump system and UV-Vis Spectrophotometer. Both involved the use of l(+) and d(?) LDH enzymes, with the reduction of NAD⁺ to NADH₂ measured at 340 nm. These enzymatic methods are highly specific for either isomer, run at a rate of 60 samples/hr, use minimal quantities of reagents, and require only 40 to 80 μl of sample.