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HelpTest ID SPECI Specimen Source Identification
Useful For
Determining specimen origin when the patient identity of a specimen is in question
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| _STR1 | Comp Analysis using STR (Bill only) | No | No |
| _STR2 | Add'l comp analysis w/STR (Bill Only) | No | No |
Special Instructions
Method Name
Microsatellite markers are used to compare the genotype for the specimen in question with that from DNA isolated from patient specimens of known identity.
(Polymerase chain reaction [PCR] is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)
Reporting Name
Specimen Source IdentificationSpecimen Type
VariesDue to the complex nature of this test, direct communication (eg, pathologist to pathologist) is required to avoid delays in sample processing and ensure an understanding of relevant case details.
A brief letter that includes the following 4 pieces of information is required for all orders:
1. Reason for testing, including detailed information regarding what specific comparisons are requested.
2. Clear identification of the known and unknown specimens.
3. Copies of all existing pathology reports pertaining to submitted issue specimens.
4. Contact information for the ordering physician.
Forms: New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (Supply T576) is available in Special Instructions.
Chain of custody documentation is not available. This test is not intended for medico-legal or forensic purposes.
Specimen preferred to arrive within 96 hours of draw.
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA) or yellow top (ACD)
Acceptable: Any anticoagulant
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send specimen in original tube.
Specimen Stability Information: Ambient (preferred)/Refrigerated
Specimen Type: Tissue block or slide
Collection Instructions:
1. Submit formalin-fixed, paraffin-embedded (FFPE) tissue block (preferred) or 4 to 10 unstained sections (each 5 micron-thick) plus 1 slide stained with hematoxylin and eosin.
2. The number of unstained sections required depends on the amount of tissue that can be used for analysis.
3. For very small tissue fragments, 10 sections are recommended; for large tissue fragments, 4 sections are generally sufficient.
4. If known and unknown specimens are within the same block, include labeled hematoxylin-and-eosin slide identifying the known and unknown specimens.
5. Specimen ID tests involving very small fragments of tissue, including most floaters are performed at the discretion of the reviewing pathologist. Cases involving floaters are usually rejected due to an insufficient amount of the floater tissue.
Specimen Minimum Volume
Blood: 0.5 mL/Tissue: send paraffin-embedded whole tissue OR 4×5 micron-thick sections plus 1 H/E slide
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Varies | |
Clinical Information
For various reasons, the patient origin for a particular specimen may be questioned. This is especially true for paraffin-embedded material: labeling accuracy may be questioned or tissue from other sources may be included by mistake. Confirmation of the patient origin may be critical to the clinical workup of that patient.
Molecular methods are now available to extract DNA from various sources, including paraffin-embedded material, and to compare the molecular fingerprint (genotype) of one specimen source with another one. Matching genotypes on multiple specimens suggest that they are derived from the same patient, whereas differences in genotype suggest different patient sources.
Cautions
Errors in our interpretation of results may occur if information given is inaccurate or incomplete.
A previous bone marrow transplant from an allogenic donor will interfere with testing. Call Mayo Medical Laboratories for instructions for testing patients who have received a bone marrow transplant.
Chain-of-custody documentation is not available.
This test is not intended for use in forensic or medicolegal cases; the use of this assay for these purposes is strongly discouraged.
Day(s) Performed
Monday, Wednesday; 10 a.m.
Report Available
14 daysPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
81265-Comparative analysis using Short Tandem Repeat (STR) markers; patient and comparative specimen (eg, pre-transplant recipient and donor germline testing, post-transplant non-hematopoietic recipient germline [eg, buccal swab or other germline tissue sample] and donor testing, twin zygosity testing or maternal cell contamination of fetal cells
Added as needed:
81266 each additional specimen (eg additional cord blood donor, additional fetal samples from different cultures, or additional zygosity in multiple birth pregnancies)