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Collecting DNA Evidence at Property Crime Scenes

Control Samples

Control Samples

Control samples, sometimes referred to as substrate samples, are swabbings or cuttings from an unstained portion of the surface material near the recovered stain. The control sample should be packaged separately and clearly labeled. A laboratory may use the substrate samples as a control to confirm that the results of the test performed were brought about by the stain and not by the material on which it was deposited. Additionally, the laboratory can use these controls to troubleshoot unexpected results.

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