Enzymes. DNA polymerase or deoxynucleoside triphosphate : DNA deoxynucleotidyl-transferase (EC 2.7.7.7); pancreatic DNAase or deoxyribonuclease oligonucleotidohydrolase (EC 3.1.4.5) ; venom phosphodiesterase or orthophosphoric diester phosphohydrolase (EC 3.1.4.1); alkaline phosphataae or orthophosphoric monoester phosphohydrolase.Definition. A,, unit, the quantity of material contained in 1 ml of a solution which has an absorbance of 1 at 260 nm, when measured in a I-cm pathlength cell. 11'sico-chemical data which lead to the conclusion that this biopolymer does not have a Watson-Crick structure are presented in a subsequent publication [6].