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UV Irradiation and Autoclave Treatment for Elimination of Contaminating DNA From Laboratory Consumables

NCJ Number
Forensic Science International: Genetics Volume: 4 Issue: 2 Dated: February 2010 Pages: 89-94
Lisa A. Gefrides; Mark C. Powell; Michael A. Donley; Roger Kahn
Date Published
February 2010
6 pages
This article reports on a systematic study of UV and autoclave treatments on the persistence of DNA from saliva. This study was undertaken to determine the best decontamination strategy for the removal of DNA from laboratory consumables.
Laboratories employ various approaches to ensure that their consumables are free of DNA contamination. They may purchase pretreated consumables, perform quality control checks prior to casework, and use in-house profile databases for contamination detection. It is better to prevent contamination prior to DNA typing than identify it after samples are processed. To this end, laboratories may UV irradiate or autoclave consumables prior to use, but treatment procedures are typically based on killing microorganisms and not on the elimination of DNA. Autoclave and UV irradiation procedures that can eliminate nanogram quantities of contaminating DNA contained within cellular material are identified. Autoclaving is more effective than UV irradiation because it can eliminate short fragments of contaminating DNA more effectively. Lengthy autoclave or UV irradiation treatments are required. Depending on bulb power, a UV crosslinker may take a minimum of 2 hours to achieve an effective dose for elimination of nanogram quantities of contaminating DNA (greater than 7,250 mj/cm2 ). Similarly, autoclaving may also take 2 hours to eliminate similar quantities of contaminating DNA. For this study, dried saliva stains were used to determine the effective dose. Dried saliva stains were chosen because purified DNA as well as fresh saliva are less difficult to eradicate than dried stains and also because consumable contamination is more likely to be in the form of a collection of dry cells. Tables, figures, and references (Published Abstract)