Dimensional, Osmotic, and Chemical Changes of Erythrocytes

Previous studies have indicated that acid glucose-citrate solutions provide the best preservation available at the present time (1). The mixture proposed by Loutit and Mollison (2, 3), conventionally called ACD-I in the United States, has been most extensively studied and appears unsurpassed in its preservative qualities. It is added in amounts of 25 ml. per 100 ml. of blood. The study to be reported was undertaken with the aim of defining the minimal amount of acid citrate-glucose diluent compatible with optimal preservation of blood. With this in mind a comparison was instituted among 3 acid citrate-glucose solutions so adjusted as to produce the same degree of acidity and the same citrate concentration as is achieved with ACD mixture, even though they were added in amounts of 15, 20, and 25 ml. per 100 ml. of blood (originally designated ACD-G, H, K). On the basis of previous data which indicated that only about 0.2 gram of glucose were glycolyzed by 100 ml. of blood during the usual storage periods, the glucose content of these solutions was reduced to % of that in ACD-I. Since the anticipated differences between the preservatives were small compared with the variability between individual bloods, the experiment was conducted with special attention to randomization of the variables concerned. By its arrangement this study afforded an opportunity to assess the variability among different bloods treated in the same way and to compare it with the variability among several samples of one blood treated in a different way.