Molecular Diagnostics Laboratory

Specimen Requirement Information

General Specimen Requirements

Peripheral blood specimens (3-5ml) collected in yellow - or purple-topped tubes (ACD or sodium EDTA anticoagulant, respectively) should be delivered or shipped at ambient temperature to the laboratory at the address below. Bone marrow specimens (1 ml minimum) should be drawn into a syringe containing anticoagulant and then shipped in EDTA tubes.

Special Specimen Requirements

Specimens Requiring RNA Isolation

Specimens for BCR-ABL or PML-RARa translocation analyses require isolation of RNA from the cells and special handling is required to preserve the integrity of the RNA. Peripheral blood or marrow should be collected as above in ACD or EDTA tubes, placed on ice, and immediately delivered or shipped to the lab. Do not freeze whole blood or marrow. Overnight storage of the specimen may compromise the quality of the RNA required for testing or produce a false negative result. If necessary, blood or bone marrow samples may be refrigerated for up to 48 hours until delivery except when testing for minimal residual leukemia, in which case prompt delivery is essential.

Solid Tumor/ Frozen Tissue Specimens

Lymph node tissue or skin biopsy may be utilized as a source of DNA for molecular assays. Each should be obtained in a sterile manner and delivered to the lab within 3 hours of collection, or snap frozen at -70o C (and transported frozen) to preserve DNA integrity. A minimum of three cubic millimeters of tissue is required for molecular testing.

Fixed, paraffin-embedded tissue specimens may also be used as a source of DNA for selected PCR based assays (IgH, TCR, bcl1, bcl2). Please note that for fixed tissue specimens, only formalin fixation provides dependable results. Zenker's, B5, or Bouin's fixatives all produce extensive degradation of DNA, making their use inappropriate for molecular studies.


Please direct any additional questions regarding specimen requirements to the Molecular Diagnostics Laboratory (210) 567-4102 or Fax: (210) 567-2367 , E-mail:

Specimens should be delivered to:

Molecular Diagnostics Laboratory
Department of Pathology, Room 345D
The University of Texas Health Science Center at San Antonio
7703 Floyd Curl Drive
San Antonio TX 78284-7750