to determine whether the phosphorylation of the pdgf receptor from isolated membranes differed from the analogous phosphorylation in intact cells , sparse and confluent fibroblasts were metabolically labeled with [ 32p ] h3po4 , stimulated with pdgf , solubilized , and the cell proteins were immunoprecipitated with a phosphotyrosine-specific antibody .
C0016030
fibroblasts
C0007634
cell