[Preparation of 5-(125)iodine-2'-deoxyuridine triphosphate and incorporation of the labeled nucleotide into DNA by polymerase chain reaction]

Radioiodine was substituted into deoxyuridine triphosphate by radioiodination of 5-mercuri-2'-deoxyuridine triphosphate. The purified 125I-nucleotide was incorporated into DNA in reactions by the protocol of the polymerase chain reaction. The incorporation of the radioactive nucleotide required added thymidine triphosphate for the synthesis of full length molecules during the one minute elongation period. The iodine substituent in the DNA remained covalently bound during both heat and alkaline denaturation.