Comparison of various immunochemical assays for the detection of ethylene oxide-DNA adducts with monoclonal antibodies against imidazole ring-opened N7-(2-hydroxyethyl)guanosine: application in a biological monitoring study.
Monoclonal antibodies have been developed for the analysis of the predominant lesion in DNA induced by ethylene oxide (EtOx), namely N7-(2-hydroxyethyl)guanine (N7-EtOHGua). Two monoclonal antibodies raised against imidazole ring-opened N7-(2-hydroxyethyl)guanine (RON7-EtOHGua), N7EO-E and N7EO-11, and the previously isolated antibody N7E-102 were characterized by competitive ELISA with various inhibitors. N7EO-E and N7EO-11 recognize 2-hydroxyethyl lesions better than ethyl or methyl lesions, while N7E-102 recognizes 2-hydroxyethyl and ethyl modifications equally well. All antibodies show a preference for imidazole ring-opened adducts, bind better to adducts in DNA compared to alkylated nucleosides or bases and bind 10(6)- to 3 x 10(6)-fold less well to unmodified DNA. The sensitivity of detection of RON7-EtOHGua in DNA and in the nuclei of cells in situ by antibody N7EO-E was investigated in several assays. The immunoslot blot assay was the most sensitive method (0.34 RON7-EtOHGua per 10(6) nucleotides was detectable), followed by competitive ELISA, direct ELISA and in situ detection by immunofluorescence microscopy. The immunoslot blot assay was used to analyse N7-EtOHGua levels in white blood cell DNA from individuals exposed to EtOx (2-5 p.p.m.) and of controls. This exposure did not result in a statistically significant increase in the N7-EtOHGua level.
van Delft
J H
JH
TNO Nutrition and Food Research Institute, Department of Genetic Toxicology, Rijswijk, The Netherlands.
van Winden
M J
MJ
Luiten-Schuite
A
A
Ribeiro
L R
LR
Baan
R A
RA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000302:isolation & purification; D000918:Antibody Specificity; D002467:Cell Nucleus / Q000737:chemistry; D004247:DNA / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D018736:DNA Adducts / Q000032:analysis* / Q000378:metabolism; D004249:DNA Damage; D004797:Enzyme-Linked Immunosorbent Assay; D005027:Ethylene Oxide / Q000032:analysis* / Q000378:metabolism / Q000633:toxicity; D006147:Guanine / Q000031:analogs & derivatives* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007962:Leukocytes / Q000737:chemistry; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008856:Microscopy, Fluorescence; D016273:Occupational Exposure; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D018736:DNA Adducts; C035018:N(7)-hydroxyethylguanine; D006147:Guanine; D004247:DNA; D005027:Ethylene Oxide