Quantitation of the Folate Binding Protein in Human Cerebrospinal Fluid by an Enzyme-linked Immunosorbent Assay (ELISA)

Abstract

Summary An enzyme-linked immunosorbent assay (ELISA) was calibrated and used for quantitation of the folate binding protein in human cerebrospinal fluid. The precision of the assay in terms of the coefficient of variation was 6.3% intra-assay (10 replicate single determinations) and 4.8% inter-assay (8 duplicate determinations). The concentration of folate binding protein in cerebrospinal fluid specimens from 20 patients with no complaints or diseases of neurological type was 0.14-0.38, 0.24 nmol FBP/I (range and median value). The gelfiltration profiles of radioligand bound and immunoreactive folate binding protein were identical, both consisting of one major peak (M, '" 25000) and one minor peak (M, '" 1 00000).