Contamination is a major hurdle in the forensic laboratory. It can be caused both by primary transfer (i.e. direct transfer of contaminating DNA from an analyst or other person in the laboratory to the sample) and secondary transfer (i.e. transfer of contaminating DNA to an object used in the laboratory and subsequently from this object to the sample). It was shown and proved that cellular, purified and amplified DNA can accumulate on working surfaces or on tools and equipments handled within the laboratory environment and may have potential to get transferred to evidence samples. Contaminated equipment may thus act as a vector for transfer of DNA and DNA containing material, as contamination is a critical issue in the analysis and interpretation to trace DNA. Van Oorschot et al. emphasizes the importance of frequent and thorough cleaning of work areas and routine decontamination of all fixed and non fixed equipment. In most laboratories, sodium hypochlorite (NaOCl or bleach) is used as a decontaminating solution. As an alternative for the conventionally used sodium hypochlorite, different commercial decontamination solutions are available in the market. The potentiality of sodium hypochlorite and other available decontaminating solutions are not yet studied and analyzed as far as our knowledge concerned.
Last date updated on July, 2014