Immunoenzymatic method for detection of terminal deoxynucleotidyl transferase by light and electron microscopy

Methods for using rabbit polyclonal and mouse monoclonal antibodies to detect terminal deoxynucleotidyl transferase (TdT) in human leukemia lines were developed. Use of 1% paraformaldehyde in 0.1 M Na cacodylate buffer, pH 7.6, as a fixative provides a procedure that can be used for immunofluorescence, immunoalkaline phosphatase (APAAP), or horseradish peroxidase conjugate detection procedures in these cell lines. The peroxidase procedure can also be used for electron microscopy, clearly demonstrating nuclear localization of TdT in interphase nuclei of TdT-positive cells.