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Saliva

Home > Forensic Biology > Testing of Body Fluids & Tissues > Saliva

Saliva is the fluid that moistens the mouth.  It is secreted from three sets of glands – the sublingual, submandibular, and parotid.  The saliva from the parotid glands contains amylases, which aid in the digestion of carbohydrates.

Saliva can be the source of evidence in sexual offenses where oral contact is alleged, bite marks, or on cigarette butts discarded at a scene.

Screening for saliva is based on detection of high levels of amylase in the sample. It is not a confirmatory test as amylase is found in other body fluids.05

Saliva contains ABH substances, especially in secretors.  Saliva samples (spit or buccal swabs) are often taken as reference materials for determination of secretor status.  Stains can be typed using absorption-elution or absorption-inhibition. 

Saliva is also a rich source of DNA and buccal swabs are routinely collected for reference DNA typing.

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© 2007 NFSTC Science Serving Justice®
NOTE TO USERS: The President’s DNA Initiative DNA Analyst Training program and assessment were completed and published in 2005, in cooperation with the National Institute of Justice. The science and techniques in the program are sound and proven, however, program content has not been updated to include tools and technologies developed and in use after 2005, including many kits and robots. Assessment questions address only content delivered in this program and may not contain the full range of tools in use in your laboratory.