This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Pinkel, D. Articles by Vanderlaan, M. Search for Related Content PubMed PubMed Citation Articles by Pinkel, D. Articles by Vanderlaan, M.

Measurement of Sister Chromatid Exchanges at Very Low Bromodeoxyuridine Substitution Levels Using a Monoclonal Antibody in Chinese Hamster Ovary Cells¹

Lawrence Livermore National Laboratory, Biomedical Sciences Division, University of California, Livermore, California 94550

A monoclonal antibody to bromodeoxyuridine (BrdUrd) incorporated into DNA allowed visualization of sister chromatid exchanges (SCE) when as little as 0.6% of the thymine in a single DNA strand has been substituted. Measurement of the SCE frequency as a function of BrdUrd substitution in a normal Chinese hamster ovary cell line showed a plateau of six SCEs per cell for substitution levels up to at least 20%. A clear elevation in frequencies was noted at 60% substitution. However, in the mutant line EM9, previously shown to have a highly elevated frequency of SCE, the level of exchanges declined continuously as the percentage of BrdUrd substitution decreased. At 0.6% substitution, the frequency of SCE was still 4-fold higher than that of the parental cells. The antibody procedure described here should be useful in evaluating the extent to which SCEs induced by mutagenic agents result from interactions between the DNA damage caused by the agent and the BrdUrd routinely used for measuring SCE.

¹ Work performed under the auspices of the United States Department of Energy by the Lawrence Livermore National Laboratory under contract W-7405-ENG-48 with support from USPHS Grant CA14533 (J. G., M. V.).

² To whom requests for reprints should be addressed.

Received 6/ 6/85. Revised 8/12/85. Accepted 8/13/85.