The immunoprecipitation assay with Ruc-p53 and a clinical serum sample. A: The immunoprecipitation activity is proportional to incubation time. Tubes containing identical amounts of Ruc-p53 fusion protein extract (5 μl), patient 34 sera (1 μl) and protein A/G beads were incubated for 5, 30, 60, 90 and 120 min and processed for luciferase activity. B: Immunoprecipitation activity with various amounts of total crude patient 34 sera. Different amounts of patient sera (0.002 to 2 μl) were mixed with 5 μl of the Ruc-p53 fusion protein extract and incubated for 1 hour in the presence of protein A/G beads, processed and light units measured. The data shown is from one of three independent experiments giving similar results.