Metabolic labeling of bcl-2 from OCI/AML-5 cells in vivo (left) and in vitro (right). Radioautographs of labeled protein from control, ATRA-treated and taxol-treated cells, separated by 12.5% SDS-PAGE are shown at the top. Densitometer readings are shown. At the bottom, Western blots of the lysates, stained with anti–bcl-2, are shown. Such Western blots, prepared after 12.5% SDS-PAGE, show bcl-2 from taxol-treated cells only as a single band.