Storage requirements for erythrocytes used to culture Plasmodium falciparum.

Erythrocytes stored for up to 84 days in citrate-phosphate-dextrose (CPD), CPD-adenine, saline-glucose, saline-glucose-adenine, or as packed cells were tested after varying lengths of time for suitability to support cultures of Plasmodium falciparum using the Petri dish-candle jar technique. All storage protocols were adequate for 21 to 28 days with those media containing adenine being generally better and packed cells poorer than CPD. Erythrocyte ATP contents generally correlated well with the suitability of stored erythrocytes for supporting falciparum parasite cultures. However, rejuvenation procedures, which markedly elevated ATP concentrations in erythrocytes, resulted in erythrocytes less suitable for parasite development. Erythrocytes stored between 4 to 12 days were usually somewhat less suitable than freshly collected, or after 12-plus days of storage. The presence of leucocytes undergoing disintegration during the first week of storage had no measurable effect on the suitability of the erythrocytes because both leucocyte-rich and leucocyte-poor blood portions supported parasite development equally. Likewise, leucocytes present with parasites in the cultures, had no measurable effect on parasite development.