RPMI 1640 medium was originally developed to culture human leukaemic cells in suspension and as a monolayer. Roswell Park Memorial Institute (RPMI) 1640 Medium has since been found suitable for a variety of mammalian cells, including HeLa, Jurkat, MCF-7, PC12, PBMC, astrocytes, and carcinomas. RPMI has successfully been used for the cultivation of normal human and neoplastic leukocytes. It is now a popular general purpose medium when properly supplemented.
RPMI 1640 medium is unique from other media because it contains the reducing agent glutathione and high concentrations of vitamins. It contains biotin, vitamin B12, and PABA, which are not found in Eagle's Minimal Essential Medium or Dulbecco's Modified Eagle Medium. In addition, the vitamins inositol and choline are present in very high concentrations. The medium contains no proteins, lipids, or growth factors. Therefore, it requires supplementation, commonly with 10% foetal bovine serum (FBS). It uses a sodium bicarbonate buffer system (2,0 g/L), and therefore requires a 5 to 10% CO₂ environment to maintain physiological pH.