(A) At the top is a 10% to 20% gradient gel showing the presence of a slower-moving isoform of bcl-2 from cells treated with taxol (middle lane). The control (left lane) and lysate from ATRA-treated cells show only a single band (right lane). The bottom is 2D gels from taxol-treated cell lysate (left) and the lysate after digestion with λ-phosphatase. These conditions permit the demonstration of the slightly larger than control molecular weight of the phosphorylated bcl-2 isoform seen after taxol. (B) Lysates from ATRA- and taxol-treated cells (above) were mixed and the mixture run as a 2D gel (below). The experiment shown is representative of two replicates.