Specimen Collection

General Specimen Requirements

Peripheral Blood (PB): 3-5 ml, collected in purple-top tubes (sodium EDTA anticoagulant), should be delivered or shipped to the laboratory promptly on wet ice at the address below. Note: do not freeze specimen before sending.

Bone Marrow (BM): 1 ml minimum should be drawn into a syringe containing anticoagulant and then delivered in purple top (sodium EDTA) tube. Note: do not freeze bone marrow before sending.

Nucleic acids: it is possible to submit cDNA, genomic DNA and/or RNA directly for testing (please contact lab before sending specimen). These specimens should be shipped promptly on dry ice for optimal preservation.

Specimens Requiring RNA Isolation

Specimens for BCR-ABL or PML-RARa translocation analyses require isolation of RNA. Special handling is required to preserve the integrity of the RNA. Peripheral blood (3-5 ml) or bone marrow aspirate (1-3 ml) should be collected in purple top (sodium EDTA) tubes, placed on ice, and immediately delivered or shipped to the lab. Overnight storage of the specimen may compromise the quality of the RNA required for testing or produce a false negative result.

If absolutely necessary, blood or bone marrow aspirate samples may be refrigerated for up to 48 hours until delivery, except when testing for minimal residual leukemia, in which case prompt delivery is essentialNote: do not freeze blood or bone marrow specimens before sending.

Solid Tumor/ Frozen Tissue Specimens

Lymph node, skin, or other tissue biopsies may be utilized as a source of DNA for molecular assays. Each specimen should be obtained in a sterile manner, and a minimum 3 mm3 of tissue is required. Fresh tissue should be delivered to the lab in RPMI 1640 culture medium at room temperature within 3 hours of collection, or snap frozen in liquid nitrogen at -70�C and packed in dry ice for delivery to preserve nucleic acid integrity. Please do not allow frozen tissues to thaw.

Paraffin-Embedded Tissue Specimens

Formalin-fixed paraffin-embedded (FFPE) tissue specimens or sections prepared on glass slides (unstained slides) may also be used as a source of DNA for selected PCR based assays. Note: for fixed tissue specimens, only formalin fixation provides dependable results. Zenker’s, B5, or Bouin’s fixatives and decalcification of bone marrow biopsy specimens by formic acid all produce extensive degradation of DNA, making their use inappropriate for molecular studies.

Submitting a Sample

    • 1. Fill out Molecular Diagnostics Laboratory (MDL) Requisition Form completely
    • 2. Choose appropriate tests
    • 3. Fill out billing information
    • 4. Send specimens to:

Molecular Diagnostics Laboratory

Department of Pathology, Room 344B
UT Health San Antonio

7703 Floyd Curl Drive
San Antonio, TX 78229-3900

Please direct any additional questions regarding specimen requirements to the Molecular Diagnostics Laboratory:

Phone: (210) 567-6599
FAX: (210) 450-2243