This reagent is based upon phosphoenolpyruvate carboxylase (PEPC) utilizing bicarbonate present in the sample to produce oxaloacetate and phosphate. Malate dehydrogenase (MDH) then catalyzes the reduction of oxaloacetate to malate and the oxidation of NADH to NAD+. The resulting decrease in absorbance can be measured at 380nm and is proportional to the amount of bicarbonate present in the sample.
