Forensic Identity Techniques for Positively Identifying the Source of a Specimen

 

Situations:

(1) 2 separate specimens from 2 possible patients (switch)

(2) 1 specimen that may be from 1 patient (does this specimen belong to this patient?)

(3) 1 specimen that may be from 2 or more patients

 

Sometimes the question is about a current specimen. At other times it may be retrospective after additional testing fails to confirm a finding in a previous specimen.

 

Forensic techniques often employ PCR and may involve use of:

(1) small tandem repeats (STR, or microsatellites)

(2) single nucleotide polymorphisms (SNP)

 

Although blood transfusion was once thought to be a possible confounding factor (related to the sensitivity provided by PCR), this has not been found to be an issue.