Using the PhosphoTracer phospho-p53 assay, the length of assay incubation time that was required to detect recombinant phospho-p53 was examined. After 15 mins, phospho-p53 concentrations of approximately 2 ng/mL were readily detected, while after 2 hour incubation, the limit of detection was approximately 0.2 ng/mL. Longer incubation times had little effect on overall limit of detection that was observed.

Using p53 assay kits, a significant increase in both p53 phosphorylation at Ser15 and accumulation of total p53, is detected in U-2 OS cells treated with doxorubicin for 18 hours (+), compared with untreated cells (-).

Using Western blot, a significant increase in both p53 phosphorylation at Ser15 and accumulation of total p53, is detected in U-2 OS cells treated with doxorubicin for 18 hours (+), compared with untreated cells (-).