title: Inter-laboratory comparison of the in vivo comet assay including three image analysis systems.
abstract: To compare the extent of potential inter-laboratory variability and the influence of different comet image analysis systems, in vivo comet experiments were conducted using the genotoxicants ethyl methanesulfonate and methyl methanesulfonate. Tissue samples from the same animals were processed and analyzed-including independent slide evaluation by image analysis-in two laboratories with extensive experience in performing the comet assay. The analysis revealed low inter-laboratory experimental variability. Neither the use of different image analysis systems, nor the staining procedure of DNA (propidium iodide vs. SYBR® Gold), considerably impacted the results or sensitivity of the assay. In addition, relatively high stability of the staining intensity of propidium iodide-stained slides was found in slides that were refrigerated for over 3 months. In conclusion, following a thoroughly defined protocol and standardized routine procedures ensures that the comet assay is robust and generates comparable results between different laboratories.
authors.affiliation: Novartis Institutes for BioMedical Research, PreClinical Safety, 4057, Basel, Switzerland.
authors.forename: Ulla
authors.initials: U
authors.lastname: Plappert-Helbig
authors.affiliation: F. Hoffmann-La Roche AG, Roche Innovation Center Basel, Pharmaceutical Science, Pharma Research and Early Development, Basel, 4070, Switzerland.
authors.forename: Melanie
authors.initials: M
authors.lastname: Guérard
mesh_terms: D000818:Animals; D020552:Comet Assay / Q000379:methods* / Q000592:standards*; D004305:Dose-Response Relationship, Drug; D005020:Ethyl Methanesulfonate / Q000008:administration & dosage / Q000633:toxicity; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007583:Jejunum / Q000187:drug effects; D008099:Liver / Q000187:drug effects; D008297:Male; D008741:Methyl Methanesulfonate / Q000008:administration & dosage / Q000633:toxicity; D011419:Propidium; D017208:Rats, Wistar; D012680:Sensitivity and Specificity
chemical_list: D011419:Propidium; D005020:Ethyl Methanesulfonate; D008741:Methyl Methanesulfonate
keywords: SYBR® Gold; jejunum; liver; propidium iodide; single cell gel electrophoresis assay