A simple immunoturbidimetric method for IgG and albumin quantitation in cerebrospinal fluid and serum

We describe a simple immunoturbidimetric method for measuring both IgG and albumin in CSF and serum, which enables the calculation of CSF indices. For each protein, only one calibration curve is used for both CSF and serum samples. The assay protocol is simple and similar for both tests. Sensitivity and versatility of the method afford measurements over a very wide range of concentrations (approx. 0.007 to 94 g/l for IgG and 0.06 to 92.40 g/l for albumin). Precision studies (triplicates for 6 runs over 15 days) gave overall CVs: less than or equal to 2.9 and 4.9% for IgG in CSF (11.5 mg/l) and serum (10.28 g/l); less than or equal to 1.3 and 1.1% for albumin in CSF (115 mg/l) and serum (76.89 g/l). Comparison studies showed good correlation with radial immuno-diffusion (r greater than or equal to 0.995 and 0.976 for IgG and albumin) and rate nephelometry (r greater than or equal to 0.967 and 0.982 for IgG and albumin). Thus, the method under investigation proved to be reliable and appears to be particularly suitable for the routine work.