Use of denaturing-gradient gel electrophoresis to study chromium-induced point mutations in human cells.
A large number of hprt-mutants were obtained by treating human lymphoblast cells (TK6) with 5 microM K2Cr2O7 for 5 hr and selecting by growth in 6-thioguanine. A combination of high fidelity polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) allowed us to measure mutant frequencies as a function of DNA sequence. Chromium(VI) induced four hotspots in a 104 bp domain of hprt exon 3. Substitutions at G:C base pairs were the predominant mutations. One of the chromium-induced hotspots was located at the same position as previously determined hydrogen peroxide and benzo(a)pyrene diol epoxide hotspots.
Department of Civil and Environmental Engineering, Whitaker College of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge.
J
J
Chen
W G
WG
Thilly
D002857:Chromium / Q000633:toxicity*; D004586:Electrophoresis / Q000379:methods; D006801:Humans; D009691:Nucleic Acid Denaturation; D017354:Point Mutation
D002857:Chromium