title: The PIT method: an automated in vitro technique for drug toxicity testing.
abstract: An automated in vitro technique for drug toxicity testing is described. Human tumor cells were cultured for 2 days in 96-well microtiter plates before the addition of serial dilutions of drugs. At day 5 the cultures were terminated by the addition of a solution containing propidium iodide, ink and triton X-100 (PIT). Triton X-100 lysed all cells, which were subsequently stained by the DNA specific fluorescing propidium iodide. The ink effectively quenched all background fluorescence. The plates were read on a computer controlled automated microscope with a photomultiplier. The results showed a linear relationship between cell number and fluorescence intensity. Reproducible dose-response curves were obtained for 6 drugs tested. A computer program calculated ID50 values, making use of adequate growth and no-growth controls.
mesh_terms: D000970:Antineoplastic Agents / Q000633:toxicity*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D005453:Fluorescence; D006801:Humans; D009369:Neoplasms / Q000473:pathology*; D017830:Octoxynol; D011092:Polyethylene Glycols; D011419:Propidium
chemical_list: D000970:Antineoplastic Agents; D011419:Propidium; D011092:Polyethylene Glycols; D017830:Octoxynol