Assessing DNA recovery from chewing gum. (January 2017)

• Record Type: Journal Article
• Authors: Eychner, Alison M; Schott, Kelly M; Elkins, Kelly M
• Is Part Of: Medicine, science and the law. Volume 57:Number 1(2017:Jan.)
• Page Start: 7
• Page End: 11
• Publication Date: 2017-01
• Subjects: Forensic DNA -- chewing gum -- DNA IQ -- PrepFiler -- Chelex -- phenol-chloroform -- QIAamp -- Quantifiler; Forensic sciences -- Periodicals; Medical laws and legislation -- Great Britain -- Periodicals; 614.105
• DOI: 10.1177/0025802416676413
• Languages: English
• ISSNs: 0025-8024

Abstract

The purpose of this study was to evaluate which DNA extraction method yields the highest quantity of DNA from chewing gum. In this study, several popular extraction methods were tested, including Chelex-100, phenol-chloroform-isoamyl alcohol (PCIA), DNA IQ, PrepFiler, and QIAamp Investigator, and the quantity of DNA recovered from chewing gum was determined using real-time polymerase chain reaction with Quantifiler. Chewed gum control samples were submitted by anonymous healthy adult donors, and discarded environmental chewing gum samples simulating forensic evidence were collected from outside public areas (e.g., campus bus stops, streets, and sidewalks). As expected, results indicate that all methods tested yielded sufficient amplifiable human DNA from chewing gum using the wet-swab method. The QIAamp performed best when DNA was extracted from whole pieces of control gum (142.7 ng on average), and the DNA IQ method performed best on the environmental whole gum samples (29.0 ng on average). On average, the QIAamp kit also recovered the most DNA from saliva swabs. The PCIA method demonstrated the highest yield with wet swabs of the environmental gum (26.4 ng of DNA on average). However, this method should be avoided with whole gum samples (no DNA yield) due to the action of the organic reagents in dissolving and softening the gum and inhibiting DNA recovery during the extraction.