Determination of terminal deoxynucleotidyl transferase on bone marrow smears by immunoperoxidase

Terminal deoxynucleotidyl transferase (TdT) is a marker of lymphoblastic disorders. Previously, the technique for determining TdT on smears was by indirect immunofluorescence. An immunoperoxidase procedure for detecting TdT on smears is reported. Results are in a comparable range with the indirect immunofluorescent technique. As discussed in this paper, TdT by immunoperoxidase may offer certain advantages over the indirect immunofluorescent procedure.