Table 1.

Assays that investigate DNA damage and repair in the brain or CNS derived cells^a

Name of assay	Purpose	Refs
In vivo mutation assay	The Big Blue transgenic mice with a  reporter gene that can be easily  isolated for detection of gene mutations.	31
Single-strand conformation  polymorphism (SSCP)	Mutation screening that detects altered  transcript from specific genes.	31
HPLC or GCMS	Detection of modified nucleosides or  bases in purified DNA.	16,31,32,  39,40
Immunohistochemistry	IgG or IgM against 8-hydroxy-  2′deoxyguanosine/8-hydroxyguanosine.	23,26,33,  37,49
Gene-specific repair  using fragment shift	The presence of ODLs is detected by the  ability of the repair enzyme to remove ODLs  in purified DNA. An absence of the gene  during hybridization in alkaline blot using  gene specific probe signifies the presence  of ODLs.	21,31,56
DNA lesions detected as  sensitive sites to DNA repair  glycolylases or nucleases  in situ	Detection of specific DNA lesions in brain  tissue as sensitive sites to the Fpg protein  or exonuclease III (FPGSS or EXOSS,  respectively) enzymes followed by  post-labeling using DNA polymerase.	24,50
Repair activity assay	Expression of enzymes that repair base  modifications, e.g., 8-hydroxy  deoxyguanosine or AP sites.	2,49
DNA strand-break assay	DNA polymerase-I for detecting SSBs with  3′OH ends.	42
In vitro PCR	Detection of DNA lesions that do not support  PCR in purified DNA.	1
The comet assay	The presence of a comet tail represents the  presence of SSBs.	35,43

^aAbbreviations: GCMS, gas chromatography and mass spectrometry; HPLC, high-pressure liquid chromatograph; ODL, oxidative DNA lesions; SSB, single-stranded break.