title: Flow cytometric evaluation of apoptosis and cell viability as a criterion of anti-tumour drug toxicity.
abstract: BACKGROUND
  Determination of the drug concentration required to kill 50% of the tumour cells (EC50) does not take into account the propensity of cells to undergo apoptosis and necrosis. These 2 parameters and the viable cells are here assessed by a flow cytometric (FC) approach using propidium iodide (PI) and FITC-Annexin V staining.
  
  
  METHODS
  A number of carcinoma cell lines of defined p53 status were exposed to cis-PtII for 24 hours, stained with PI and FITC-Annexin V and analyzed by FC. Unstained viable cells, early apoptotic cells and necrotic cells were scored separately in dual parameter plots of green fluorescence (FITC) against red fluorescence (PI) to generate dose response curves.
  
  
  RESULTS
  EC50 values for cell viability were found to be 1-4 times higher than survival data from colony assays resembling data obtained by MTT or Crystal Violet vital dye staining. Percentage apoptosis measured by Annexin V binding was in agreement with microscopic scoring of apoptotic cells after Acridine Orange staining.
  
  
  CONCLUSIONS
  The FC assay described gives a good estimate of cell viability resembling data from vital dye staining assays and provides additional information on apoptosis and necrosis. FC data from Annexin V binding and microscopic scoring after Acridine Orange staining were in excellent agreement.
authors.affiliation: Department of Radiation Oncology, Radiobiology Laboratory, Department of Pharmacology, University of Stellenbosch, Faculty of Health, Tygerberg Hospital, P.O. Box 19063, Tygerberg 7505, South Africa.
authors.forename: J
authors.initials: J
authors.lastname: Michie
authors.forename: J
authors.initials: J
authors.lastname: Akudugu
authors.forename: A
authors.initials: A
authors.lastname: Binder
authors.forename: C E
authors.initials: CE
authors.lastname: Van Rensburg
authors.forename: L
authors.initials: L
authors.lastname: Böhm
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology; D002470:Cell Survival / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000473:pathology; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents