Satisfactory Red Cell Viability with Slight Excess of Acid Citrate Dextrose

Platelet suspensions obtained from blood donors are improved by increased acidification. The simplest way to accomplish this is to collect less blood into the standard quantity of ACD. Since we have previously reported an impairment in red cell viability when blood is collected in a great excess of ACD, it became pertinent to test the survival of stored red cells collected in a "slight" excess of ACD.

The volume of the blood collected was lowered to 375 ml. in 75 ml. ACD (N. I. H. formula A). At this ratio the pH. was 6.5 which is sufficiently low to minimize platelet clumping. The red cells were separated, stored for 21 days at 4 C., and viability was tested by the ⁵¹Chromate method. The results showed adequate red cell survival for blood collected and stored in this manner.