Silica gel radioimmunoassay for myelin basic protein.

1. A radioimmunoassay which relies upon the capacity of silica gel to absorb free human basic protein of myelin (BP) is described. 2. Reagents involved in the assay include unlabelled BP, I-BP, and rabbit anti-BP. The assay is performed in excess normal rabbit serum, and uses 3-4% silica gel for absorption of free I-BP. 3. The assay is simple, reproducible and not particularly time-consuming. It is capable of detecting BP at a level of 1-10 or more nanograms in samples containing varying amounts of serum. The assay is thus highly suitable as a routine test in clinical laboratories interested in detecting BP in cerebrospinal fluid in patients with suspected or proven demyelination.