We describe a method of growing an animal cell in a culture medium, in which the culture medium comprises an elevated concentration of a thymidine family member, in which the growth or viability of the animal cell is increased as a result of the elevated concentration of the thymidine family member in the cell culture medium. Preferably, the cell culture medium comprises a semi-solid medium, which is a serum free or chemically defined medium.
Synthesis of tritium-labelled 3?-azido-3?-deoxythymidine
approaches to the synthesis of 3′-azido-3′-deoxythymidine labelled with tritium in the heterocyclic base have been developed. With this aim, enzymatic transribosylation with [3H]thymine using the enzyme preparation from rat liver and a three-step chemical synthesis with use of the tritium labelled precursor were studies. The enzyme preparation did not catalyse the transfer of the 3′-azido-3′-deoxyribosyl