The preparation of [ 125I]iododeoxyuridine-labeled oligomers by automated synthesis with an 125I-nucleoside phosphoramidite

• Published in: Applied radiation and isotopes Vol. 44; no. 4; pp. 665 - 671
• Main Author: Scherberg, Neal H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.1993
• Subjects: DIPEA, N,N diisopropylethylamine; DMT-5-IdU-CEP (ortIdU-CEP), 4,4'-dimethoxytrityl-5-iododeoxyuridine-3'[(2-cyanoethyl)- N,N-diisopropyl]-phosphoramidite; 5'-OMe-T-CEP, 5'- O-methyl-thymidine 3'-[(2-cyanoethyl)- N,N-diisopropyl]-phosphoramidite; CEP-Cl, 2-cyanoethyl N,N-diisopropyl-chlorophosphoramidite; DMT-Cl, 4,4'dimethyltrityl chloride; IdU; DMT-5-IdU
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/0969-8043(93)90129-X

DMT-5'-[ 125I]IdU CEP was prepared by a three step procedure starting with deoxyuridine. The carrier-free 125I-nucleoside phosphoramidite was unstable in a dry state, but was stabilized by the addition of 5'-OMe-T-CEP. The mixture of phosphoramidites was used to introduce the radioactive nucleotide into DNA during automated synthesis of oligomers. The 5'-OMe-T-CEP carrier acted as a chain terminator for non- 125I-containing oligomers improving the electrophoretic separation of the radioactive product. The procedure provides a simplified and more versatile method of preparing an oligomer with radioactive bases at preselected sites and with high specific activity.