In vitro changes in blood P50 and erythrocyte 2,3 diphosphoglycerate concentration

Abstract

In vitro changes in P50 and erythrocyte 2,3 diphosphoglycerate concentration occurring in blood 2 to 8 h after venipuncture were studied. When blood was incubated at 37°C, significant decreases in P50 were observed at 2, 4 and 8 h. Such a change was significantly less when blood was kept at 4°C. The rate of decrease in P50 was not changed when pH was altered by adding either lactic acid or sodium bicarbonate to the blood before incubation at 37°C for 2 h. The erythrocyte 2,3 diphosphoglycerate concentration of blood incubated at 37°C did not change by 2 h, but had significantly decreased by 4 h. To avoid in vitro changes, it is recommended that P50 be determined as soon as possible for blood sampling.