Separation of deoxythymidine-5'-triphosphatase from unspecific hydrolases. A recommended micromethod in the diagnostic evaluation of human carcinoma.

A one-step micromethod was developed to separate from human serum four different enzymes capable of hydrolysing dTTP to the respective diphosphate. According to the purification procedure, the enzymes are referred to as Fraction I, II, IIIa, and IIIb, respectively. In view of a putative tumor specificity the activities of the enzymes are investigated for five different groups, epithelial carcinoma, leukemia, and three control groups. The results indicate that an absolute tumor specificity could not be attributed to one of the enzyme fractions. The activity of Fraction I is, however, highly elevated in the sera of seriously ill patients, whereas the activity of the epithelial carcinoma and the leukemia is even slightly reduced compared to the blood donor group. These data provide evidence that the determination of Fraction IIIb along with Fraction I can reduce the false positive rate to a great extent.