THE PRESENCE OF TRANSCRIPTION FACTORS IN FETAL BOVINE SERA

Three sources of fetal bovine serum (FBS) were fractionated by ammoniu m sulfate precipitation and by sodium dodecyl sulfate-polyacrylamide g el electrophoresis (SDS-PAGE), transferred to Immobilon-P membranes, i mmunoblotted with a panel of transcription factor antibodies, and dete cted by enhanced chemiluminescence. Nine transcription factors were de tected-ATF-2, SRE-ZBP, GATA-2, TFIID, Ets-1/Ets-2, E2F-1, Oct-2, p53, and AP-2; four transcription factors were not detected-Myo D, CREB, Sp 2, and Wilms' tumor. The results indicated the presence of varying amo unts of several transcription factors in three commercial sources and may represent heretofore unrecognized factors influencing cell culture .