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Use of Frozen Tissue in the Comet Assay for the Evaluation of DNA Damage
Published on: March 24, 2020
Mercury concentration in frozen whole-fish homogenates is insensitive to holding time
Spencer A Peterson1, David V Peck, John Van Sickle
1Western Ecology Division, US Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, 200 SW 35th Street, Corvallis, OR 97333, USA. Peterson.spencer@epa.gov
Abstract:
Current recommended holding times for the analysis of total mercury (Hg) in fish tissue ranges from 28 to 180 days. In 2006, we evaluated the effect of an extended holding time on Hg concentrations by reanalyzing whole-fish wet homogenates that were analyzed originally in 2002 and had been stored frozen at -20 degrees C since that time. Seven species, 13-15 samples each, were reanalyzed. Comparisons of concentration differences between 2006 and 2002 indicated that no statistically significant changes in Hg concentrations occurred in any of the seven fish species. These results indicate that wet fish tissue homogenates can be held frozen for at least four years without affecting analytical results, thus extending holding times far beyond those currently recommended.

