What is trace DNA?

Trace DNA refers to very small amounts of genetic material that are detected on an item, surface, or person.

It is typically recovered from skin cells shed during everyday contact, handling, or movement within an environment. Because only a small quantity of biological material is present, trace DNA results are often more complex to interpret than results obtained from larger biological samples such as blood or semen.

Trace DNA may arise from direct contact, but it can also result from indirect transfer, persistence from earlier interactions, or redistribution through handling and shared environments.

Laboratory testing can sometimes generate DNA profiles from trace material, but the results may be partial, mixed with DNA from other contributors, or limited by the amount and quality of the sample.

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