Clean Techniques for Handling Evidence

The emphasis on the use of clean techniques for handling evidence has increased since the advent of DNA testing in the 1980s. This article from the National Law Enforcement and Corrections Technology Center describes procedures for the safe handling of evidence that have become commonplace in crime laboratories. These procedures include: always wearing gloves and changing them between handling of different samples; using a barrier between the countertop and the sample during the analysis; opening only one sample at a time; processing items under a hood; constant cleaning of countertops and instruments that have come in contact with the samples; processing samples from known individuals separately in time or space from unknown forensic samples; and ensuring that the amplification of DNA samples is generated, processed, and maintained in a room separate from evidence extraction, DNA extractions, and amplification-setup areas.