THE VALUE OF IMMUNOHISTOCHEMISTRY
IN THE ASSESSMENT OF BONE MARROW DISORDERS

Attilio Orazi, M.D., FRCPath. and Dennis P. O'Malley, M.D.

TDT TdT is a polyclonal rabbit antibody made against thymic lymphocytes. Heat induced epitope retrieval technique is necessary for reliable staining. The stain works best in formalin fixed tissue and appears somewhat inhibited in B5-fixed tissues and after prolonged decalcification. The stain is a value in detecting lymphoblastic lymphomas and acute leukemias. References Orazi A, Cattoretti G, John K, Neiman RS: Terminal Deoxynucleotidyl Transferase staining of malignant lymphomas in paraffin sections. Mod Pathol 1994;7:582. Orazi A, Cotton J, Cattoretti G, Kotylo P, John K, Manning JT, Neiman RS. Terminal Deoxynucleotidyl Transferase staining in acute leukemia and normal bone marrow using routinely processed paraffin sections. Am J Clin Pathol 1994;102-640.