Reduced frequency of baseline sister chromatid exchanges in lymphocytes grown in antibiotics and serum-excluded culture medium

Peripheral venous blood from man; muntjac; cattle were grown in medium () containing different serum (human AB+/FCS/autologous); () without serum or antibiotics (penicillin; streptomycin); or () without both serum; antibiotics to investigate to what extent certain essential culture components used in in vitro mammalian cell cultures affect the incidence of spontaneous sister chromatid exchanges (SCEs). The observation that exclusion of only serum from culture medium enhanced the frequency of SCEs whereas exclusion of both serum; antibiotics; which influence the cell cycle kinetics to a great extent; exhibited the lowest frequency of SCEs reported so far for lymphocyte cultures; indicates that the frequency of so-called spontaneous SCEs usually observed in normal lymphocyte cultures grown in medium supplemented with serum; antibiotics is in fact an elevated frequency