A unique protein in normal human cerebrospinal fluid.

On analysis of cerebrospinal fluid (CSF) samples from normal volunteer donors by high-resolution zone electrophoresis on agarose gel, an electrophoretically homogeneous protein band consistently appeared in the gamma-globulin region. Application of immunofixation electrophoresis in attempts to identify the band with use of monospecific antibodies against individual human serum proteins and against heavy- and light-chain immunoglobulins as well as polyvalent antisera did not produce a positive immunoprecipitation reaction with the protein band. The serum samples from these subjects did not show similar bands. Therefore, we conclude that this protein band is a normally occurring protein that is unique to CSF.