title: Detection of terminal deoxynucleotidyl transferase (TdT)-positive leukemia cells by an immunoperoxidase staining.
abstract: Several conditions for the immunoperoxidase staining on terminal deoxynucleotidyl transferase (TdT) were surveyed in leukemic cells. Fixation of the slides in methanol containing 0.03% hydrogen peroxide for 30 min obliterated endogenous peroxidase completely. Pretreatment of the slides with normal goat serum diminished nonspecific staining effectively. Replacement of rabbit anti-TdT serum with non-immune rabbit IgG gave negative staining in the slides from TdT+ cases. The presence or the absence of TdT and % TdT+ cells determined by this method were in concordance with those assessed by immunofluorescence (IF) or by biochemical assay. Therefore, the immunoperoxidase staining provides an easy and dependable method to survey TdT by bright-field microscopy. The peroxidase+ small granules were detected in the nucleus of the blasts from TdT+ ALL cases. However, in two of four cases with CML in blast crisis peroxidase+ granules were distributed in the cytoplasm as well as in the nucleus. This finding suggests that blasts of some CML cases in blast crisis have phenotypic characteristics similar to some population of TdT+ cells in thymocytes.
mesh_terms: D000328:Adult; D000368:Aged; D001853:Bone Marrow / Q000201:enzymology* / Q000473:pathology; D004253:DNA Nucleotidylexotransferase / Q000032:analysis*; D004254:DNA Nucleotidyltransferases / Q000032:analysis*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007124:Immunoenzyme Techniques; D007945:Leukemia, Lymphoid / Q000201:enzymology* / Q000473:pathology; D007951:Leukemia, Myeloid / Q000201:enzymology* / Q000473:pathology; D008297:Male; D008875:Middle Aged
chemical_list: D004254:DNA Nucleotidyltransferases; D004253:DNA Nucleotidylexotransferase