Practice question

RPMI-1640 originally developed by George Moore, Robert Gerner, and Herbert Franklin at Roswell Park Memorial Institute Buffalo New York 1967 for establishment of human lymphoblastoid cell line number 1640 from peripheral blood without fibroblast feeder layer, tailored specifically to suspension hematopoietic cells with distinct requirements versus adherent fibroblasts. Distinguishing features include low calcium 0.42 mM versus 1.8 mM in DMEM reducing cadherin mediated homotypic aggregation causing clumping and death of suspension lymphocytes, high inorganic phosphate 5.6 mM versus 1.0 mM supporting high nucleotide synthesis demand during rapid S phase, reduced bicarbonate 24 mM versus 44 mM compatible with 5 percent CO2 avoiding alkaline drift detrimental to lymphocytes sensitive to pH above 7.7 where interleukin-2 receptor alpha signaling diminished, and enhanced vitamin repertoire including biotin cofactor for acetyl-CoA carboxylase, vitamin B12 for methionine synthase, para-aminobenzoic acid precursor folate supporting rapidly dividing immune cells lacking storage. Glucose modest 2 grams per liter prevents lactate overproduction, glutathione reducing agent plus phenol red indicator present.