RPMI-1640 was developed by Moore, et al., at Roswell Park Memorial Institute, hence the acronym RPMI.�The formulation is based on the RPMI-1630 series of media utilizing a bicarbonate buffering system and alterations in the amounts of amino acids and vitamins.�RPMI-1640 medium has been used for the culture of human normal and neoplastic leukocytes.�RPMI-1640, when properly supplemented, has demonstrated wide applicability for supporting growth of many types of cultured cells, including fresh human lymphocytes in the 72 hour phytohemaglutinin (PHA) stimulation assay.