Fig. 4.
Biosynthetic labeling of pRb. Indicated U-937 clones were biosynthetically labeled for 2 hours with 35S-methionine/cysteine and labeled proteins were subjected to immunoprecipitation with an anti-pRb antibody or a negative control antibody followed by SDS-PAGE and fluorography, as described in the Materials and Methods. Molecular weights are indicated to the left (in kilodaltons). Immunoprecipitated pRb is indicated with an arrow.
