“…For purposes of comparison, a modification of the chemically defined medium (medium 5; 18AA-B) of Wu and Bergdoll (17) was also tested. This 18AA-B medium contained the vitamins and inorganic salts listed in Table 1, along with 18 amino acids at concentrations described for medium 5 of Wu and Bergdoll (17): aspartic acid (1,200 jg/ml), isoleucine (300 usg/ml), alanine (1,200 gg/ml), lysine (300 ug/ml), tryptophan (30 ug/ml), serine (2,400 Mg/ml), glutamic acid (1,200 Mg/ml), methionine (90 Mg/ml), histidine (240 ug/ml), tyrosine (100 Mg/ml), threonine (2,400 Mg/ml), glycine (1,200 Mg/ml), leucine (300 Mg/ml), valine (240 MLg/ml), proline (1,200 Mg/ml), cystine (120 Mg/ml), phenylalanine (100 Mig/ml), and arginine (360 Mglml). No designated carbon source, such as the 1% MSG added to all other defined media, was used in the 18AA-B medium.…”