Quantitative and qualitative assessment of DNA extracted from saliva for its use in forensic identification

Saliva has long been known for its diagnostic value in several diseases. It also has a potential to be used in forensic science.

The objective of this study is to compare the quantity and quality of DNA samples extracted from saliva with those extracted from blood in order to assess the feasibility of extracting sufficient DNA from saliva for its possible use in forensic identification.

Blood and saliva samples were collected from 20 volunteers and DNA extraction was performed through Phenol Chloroform technique. The quantity and quality of isolated DNA was analyzed by spectrophotometery and the samples were then used to amplify short tandem repeat (STR) F13 using the polymerase chain reaction.

Mean quantity of DNA obtained in saliva was 48.4 ± 8.2 μg/ml and in blood was 142.5 ± 45.9 μg/ml. Purity of DNA obtained as assessed by the ratio of optical density 260/280, was found to be optimal in 45% salivary samples while remaining showed minor contamination. Despite this positive F13 STR amplification was achieved in 75% of salivary DNA samples.

Results of this study showed that saliva may prove to be a useful source of DNA for forensic purpose.