QUANTITATIVE-DETERMINATION OF TRANSFERRIN IN CEREBROSPINAL-FLUID USING AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY

An enzyme linked immunosorbent assay (ELISA) based method for the dete rmination of transferrin in cerebrospinal fluid (CSF) is described. Th is method allows transferrin determinations in ultra-small (less than or equal to 5 mu L) sample volumes. The proposed method offers the pos sibility to determine transferrin at very low concentrations at which existing methodologies fail because of their insufficient detection li mits. The accuracy of the proposed technique was validated by comparin g the results of 20 CSF samples obtained by ELISA to those measured by nephelometry yielding mean +/- SD values of 21.1 +/- 5 mg/L and 20.6 +/- 6 mg/L, respectively (y = 1.13X - 2.97, r = 0.899). The interassay CV was below 10% whereas the detection limit was 2.9 mu g/L.