Abstract
Acid citrate pH 6.5 protects human platelets from activation during washing at room temperature. Platelets suspended in media containing citrate pH 6.5 have an extra-flat disc shape. Citrate at pH 6.5 also inhibits the ADP-induced shape change. When warmed to 37.degree. C and suspended into the test medium of pH 7.4, the washed platelets aggregate with low concentrations of ADP or epinephrine in the presence of fibrinogen and Ca2+. The morphological and functional quality of platelet concentrates (6 .times. 106 .mu.l-1) stored in acid citrate pH 6.5 is maintained for at least 6 h at room temperature.