Quantitation of plasma levels of 8-methoxypsoralen by competitive enzyme-linked immunosorbent assay.
An immunologic method for the quantitation of 8-methoxypsoralen (8-MOP) levels in human plasma has been developed. A monoclonal antibody recognizing 8-MOP was prepared by immunizing mice with an 8-MOP derivative conjugated to bovine serum albumin with 1-ethyl-3-(3-dimethylamino-propyl)-carbodiimide-HCl. The antibody was characterized by competitive enzyme-linked immunosorbent assay (ELISA) and recognizes 8-MOP (50% inhibition at 2 pmol) as well as structurally related psoralen derivatives including 4'-aminomethyl-4,5',8-trimethylpsoralen (50% inhibition at 50 pmol), 5-methoxypsoralen (50% inhibition at 150 pmole), and 6,4,4'-trimethylangelicin (50% inhibition at 360 pmol). The assay has a limit of sensitivity of 1 ng/ml plasma. For analysis of 8-MOP levels in plasma, samples were first extracted using SepPak C18 cartridges. The extracts were analyzed for 8-MOP levels both by ELISA and high-pressure liquid chromatography. There was a good correlation between the values determined by both methods (r = 0.92, p less than 0.0005). The development of immunologic methods should greatly facilitate the quantitation of 8-MOP levels in patient plasma.
Yin
B Y
BY
Division of Environmental Sciences, School of Public Health, Columbia University, New York, NY 10032.
Gasparro
F P
FP
Bevilacqua
P M
PM
Santella
R M
RM
D000818:Animals; D000911:Antibodies, Monoclonal; D001774:Blood Chemical Analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D008730:Methoxsalen / Q000032:analysis*; D051379:Mice; D008807:Mice, Inbred BALB C; D008832:Microchemistry
D000911:Antibodies, Monoclonal; D008730:Methoxsalen