Test Code TDTM Terminal Deoxynucleotidyl Transferase (TdT) Stain

Performing Laboratory

NRL-Flow Cytometry

Flow Cytometry/Fluorescent Stain

Submit only 1 of the following specimens:

Specimen Type: Bone marrow aspirate, body fluid, or spinal fluid

Container/Tube: Green top (sodium heparin)

Specimen Volume: 1 mL

Collection Instructions: Label specimen as bone marrow aspirate or type of fluid.

Specimen Type: Blood

Container/Tube: Green top (sodium heparin)

Specimen Volume: 1 mL

Collection Instructions: Label specimen as blood.

Ambient

Monday through Friday

TdT is present in immature but not mature lymphocytes.

TdT is not normally seen in peripheral blood lymphocytes but is positive in 1% to 2% of normal bone marrow lymphocytes.

Strong TdT reactivity is found in 90% to 95% of acute lymphocytic leukemias and lymphoblastic lymphomas.

88180-Flow cytometry

88347-Stain