p53 expression in cultured cells following radioisotope labelling.

p53 inhibits division following cellular damage. Cultured cells were found to express p53 protein following pulse labelling with radioisotopes, even at low doses normally used for growth and metabolic labelling studies. Some stem cells are exquisitely sensitive to radiation and thus p53 may have evolved as a major regulator of stem cell function. Therefore any genetic damage may be able to induce p53 expression, which in turn will affect the biochemical outcome of many experiments by both cell cycle arrest and other mechanisms. In some cases the use of radioisotopes may directly change the results of the experiment. This will require a careful re-evaluation of the current literature and experimental protocols utilising radioisotopes.