title: A convenient fluorescent-labeled assay for in vitro measurement of DNA mismatch repair activity.
abstract: OBJECTIVE
  The assay of DNA mismatch repair (MMR) activity can be used as a biomarker for environmental condition detection and human disease diagnosis. Radioactive ³²P-endlabeled DNA containing mismatch is extensively used as the substrate for MMR activity analyses. The aim of the present study is to develop a simple non-radioactive, but equally specific and sensitive method for the MMR activity assay.
  
  
  METHODS
  A fluorescent label was chosen to replace the radioactive isotope label. Sensitive evaluation of the fluorescent label was carried out for the first time, and then the fluorescent label was compared with the isotope label in the MMR activity and DNA binding assays.
  
  
  RESULTS
  LOD (limit of detection) of the fluorescent label was about 0.1 fmol and the relative signal strength displayed a pretty good linear relationship. Moreover, the fluorescent label method has equivalent sensitivity and performance as compared with the classical radioactive method in experiments.
  
  
  CONCLUSIONS
  In light of the sensitivity, reproducibility, safety, rapidity and long lifespan of the fluorescent label, this improved method can be applied to evaluation of biologic and toxic effects of environmental pollutants on man and other forms of life.
authors.affiliation: The State Key Laboratory of Pharmaceutical Biotechnology and Jiangsu Center of Hepatobiliary Diseases, School of Stomatology and Affiliated Stomatological Hospital, Nanjing University, Nanjing 210093, Jiangsu, China.
authors.forename: Shi-Ying
authors.initials: SY
authors.lastname: Li
authors.forename: Xiang-Yu
authors.initials: XY
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Lan
authors.forename: Zi-Chun
authors.initials: ZC
authors.lastname: Hua
mesh_terms: D053843:DNA Mismatch Repair / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D006801:Humans; D012680:Sensitivity and Specificity