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Alternative Name
Specimen Identity
Test Description

STR (short tandem repeat) analysis by PCR and capillary electrophoresis (fragment analysis) is used to define sample identity and to identify mixtures of two or more genotypes within a single sample. Fifteen autosomal markers and one gender-based marker are analyzed. 

Clinical Significance

This test is useful to confirm specimen patient identity in cases of questionable sample labelling or origin and for differentiating partial moles from complete hydatidiform moles (molar pregnancy). Note: when used for specimen identity, this assay is not performed as a clinical assay for patient care.

Specimen Requirements

Notes: For analysis of suspected molar pregnancy, please submit a maternal blood sample along with the POC (products of conception) sample. For specimen ID confirmation, additional patient samples may be needed for comparison. Please call before sample submission to discuss details of atypical cases.

  • Peripheral blood: 5 mL in EDTA tube.
  • Bone marrow: 2 mL in EDTA tube.
  • FFPE tissue: Paraffin block is preferred. Alternatively, send 1 H&E slide plus 5-10 unstained slides cut at 5 or more microns. Please use positively-charged slides and 10% NBF fixative. Do not use zinc fixatives.
  • Fresh tissue: Minimum two pieces 0.2 cm3, fresh in RPMI or frozen.
  • Note: Please exclude biopsy needles, blades, and other foreign objects from transport tubes. These can compromise specimen viability and yield, and create hazards for employees.
Storage and Transportation

Use cold pack for transport, making sure cold pack is not in direct contact with specimen.

CPT Code(s)*
81265x1 or 81266x1 (if additional specimen received)
Turnaround Time

10 days

Level of Service

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.