Terminal deoxynucleotidyl transferase by IHC

Alphabetical Test listing

Terminal deoxynucleotidyl transferase by IHC-12376 - Technical only;12379 - Technical & interpretation

Terminal deoxynucleotidyl transferase by IHC
12376 - Technical only
12379 - Technical & interpretation
  • All IHC stains will include a positive control tissue
  • Tdt identifies immature T and B lymphocyte precursors in acute leukemias. It is expressed at a high level in T cell and pre-B cell ALL and lymphoblastic lymphomas
  • Tdt is very useful on bone marrow trephines of leukemias where an adequate aspirate was unable to be obtained
  • B cell ALL (Burkitt type) and mature B and T cell malignancies are Tdt negative
  • Tdt may be expressed in some cases of AML and CML (blast crisis)
  • Tdt Expression is normally seen in the thymus (as well as in thymomas) and in a few cells in normal bone marrow (corresponding to normal precursor cells)

Submit a formalin-fixed, paraffin embedded tissue block


Formalin-fixed, paraffin embedded (FFPE) tissue block


FFPE tissue section mounted on a charged, unstained slide


Ambient (preferred)

AHL - Immunohistochemistry
Mo - Fr
1 - 2 days

Immunohistochemical staining and microscopic examination


If requested, an interpretive report will be provided



  • Tdt recognizes a DNA polymerase that is present in the nuclei of normal and neoplastic T and B lymphocyte precursors

 Staining pattern

  • Nuclear based staining


  1. Orazi et. al.: TdT Staining
88342 - 1st stain
88341 - each additional stain