Monoclonal antibody to polycyclic aromatic hydrocarbons based on a new benzo[a]pyrene immunogen.
Benzo[a]pyrenebutyric acid (B[a]PBA) has been synthesized and covalently coupled to bovine serum albumin to generate monoclonal antibodies (Mab). A competitive indirect enzyme-linked immunosorbent assay (ELISA) for polycyclic aromatic hydrocarbons (PAH) has been developed with Mab B[a]P-13. It was shown by testing with 21 parent PAH and 10 compounds carrying methyl, hydroxy, or butyric acid functions that the antibody had broad specificity. Highest affinity was found for four- to six-ring PAH. Different organic co-solvents were tested. No loss in sensitivity, compared with controls in PBS, were found with methanol, dimethyl sulfoxide, and glycerol at final concentrations of 5 to 10%. Further, an observation was made that a modification (fine-tuning) of the affinity and specificity of the antibodies was possible by changing the type of the added organic co-solvent. The high susceptibility of the ELISA with regard to inorganic ions might be an indication of a more hydrophilic binding pocket e.g. involving a pi-cation interaction. Investigation of the effect of pH revealed that for pH between 6 to 9 there was no noticeable impairment. With an LOD as low as 30 pg per well for B[a]P the sensitivity of the ELISA is sufficient for analyses of solvent extracts of many environmental samples. As an example, the determination of a PAH sum parameter, given as B[a]P-equivalents, in crude aerosol extracts by both ELISA and HPLC revealed good correlation (r2=0.717) but approximately five-fold overestimation by the immunochemical method, obviously as a result of cross-reacting analytes.
Scharnweber
T
T
Institute of Hydrochemistry, Technical University Munich, Germany.
Fisher
M
M
Suchànek
M
M
Knopp
D
D
Niessner
R
R
D000393:Air Pollutants / Q000032:analysis*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D012680:Sensitivity and Specificity
D000393:Air Pollutants; D000911:Antibodies, Monoclonal; D011084:Polycyclic Aromatic Hydrocarbons