Potassium bromate as positive assay control for the Fpg-modified comet assay

Autores: Moller, P. (Autor de correspondencia); Muruzábal Gambarte, Damián; Bakuradze, T. ; Richling, E; Bankoglu, E. E. ; Stopper, H. ; Langie, S. A. S.; Azqueta Oscoz, Amaya; Jensen, A. ; Scavone, F. ; Giovannelli, L. ; Wojewodzka, M. ; Kruszewski, M. ; Valdiglesias, V. ; Laffon, B. ; Costa, C.; Costa, S.; Teixeira, J. P. ; Marino, M.; Del Bo', C. ; Riso, P. ; Shaposhnikov, S. ; Collins, A.
Título de la revista: MUTAGENESIS
ISSN: 0267-8357
Volumen: 35
Número: 4
Páginas: 341 - 347
Fecha de publicación: 2020
Lugar: WOS
The comet assay is a popular assay in biomonitoring studies. DNA strand breaks (or unspecific DNA lesions) are measured using the standard comet assay. Oxidative stress-generated DNA lesions can be measured by employing DNA repair enzymes to recognise oxidatively damaged DNA. Unfortunately, there has been a tendency to fail to report results from assay controls (or maybe even not to employ assay controls). We believe this might have been due to uncertainty as to what really constitutes a positive control. It should go without saying that a biomonitoring study cannot have a positive control group as it is unethical to expose healthy humans to DNA damaging (and thus potentially carcinogenic) agents. However, it is possible to include assay controls in the analysis (here meant as a cryopreserved sample of cells i.e. included in each experiment as a reference sample). In the present report we tested potassium bromate (KBrO3) as a positive comet assay control for the formamidopyrimidine DNA glycosylase (Fpg)-modified comet assay. Ten laboratories used the same procedure for treatment of monocytic THP-1 cells with KBrO3 (0.5, 1.5 and 4.5 mM for 1 h at 37 degrees C) and subsequent cryopreservation. Results from one laboratory were excluded in the statistical analysis because of technical issues in the Fpg-modified comet assay. All other laboratories found a concentration-response relationship in cryopreserved samples (regression coefficients from 0.80 to 0.98), although with different slopes ranging from 1.25 to 11.9 Fpg-sensitive sites (%DNA in tail) per 1 mM KBrO3. Our results demonstrate that KBrO3 is a suitable positive comet assay control.