Ultramicromethod for measuring the activity of terminal deoxynucleotidyl transferase

We describe an ultramicromethod for measurement of terminal deoxynucleotidyl transferase activity. The materials used are as proposed by Hösli (Clin Chem 1977;23:1476-84) for antenatal diagnosis. The technique is based on the methods of Beutler and Kuhl (Am J Clin Pathol 1978;70:733-7) and Yasmineh et al. (Clin Chem 1980; 26:891-5). The procedure makes it possible to reduce the blood sample to 2 mL at the most and to reduce the cost of the measurement very considerably. The technique gives results similar to those given by the conventional techniques.