Detection of DNA damage in cells exposed to ionizing radiation by use of anti-single-stranded DNA monoclonal antibody.
An immunochemical method has been developed for quantitative detection of DNA damage in mammalian cells. The method is based on the binding of a monoclonal antibody to single-stranded DNA. The clone producing this antibody (D1B) was obtained as a by-product from fusion of mouse myeloma cells with spleen cells isolated from a mouse immunized with chemically modified DNA. The technique is based upon the determination of the percentage single-strandedness resulting from the time-dependent partial unwinding of cellular DNA under alkaline conditions. Single- and double-strand DNA breaks, or lesions converted into such breaks in alkaline medium, form initiation points for the unwinding. The extent of unwinding from these points under defined conditions is a measure of the number of such sites. The method is rapid, does not require radioactive labelling of DNA or physical separation of single-from double-stranded molecules, is sufficiently sensitive to detect damage induced by 1 Gy of ionizing radiation and needs only small numbers of cells. The usefulness of the technique was demonstrated in a study of the induction of DNA damage and its repair in cultured Chinese hamster cells and in human white blood cells after exposure to 60Co-gamma-rays, and in white blood cells and bone marrow cells of X-irradiated mice. A dose-related DNA unwinding was observed and repair of DNA lesions was observed up to 60 min after irradiation.
van der Schans
G P
GP
TNO Medical Biological Laboratory, Rijswijk, The Netherlands.
van Loon
A A
AA
Groenendijk
R H
RH
Baan
R A
RA
D000818:Animals; D000911:Antibodies, Monoclonal; D001853:Bone Marrow / Q000528:radiation effects; D001854:Bone Marrow Cells; D002460:Cell Line; D006224:Cricetinae; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D004277:DNA, Single-Stranded / Q000276:immunology*; D006801:Humans; D007962:Leukocytes / Q000528:radiation effects; D051379:Mice; D008807:Mice, Inbred BALB C
D000911:Antibodies, Monoclonal; D004277:DNA, Single-Stranded; D004247:DNA