Analysis for cerebrospinal fluid proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis

Cerebrospinal fluid (CSF) proteins with molecular masses of < 150,000 Da were identified by immunoblotting after two kinds of nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). With PAGE 1 (17-27% gradient gel), CSF proteins were clearly separated into seven to nine bands with molecular masses of 3000-67,000 Da; seven bands were identified as beta 2-microglobulin, lysozyme, prealbumin, free kappa and lambda chain, apolipoprotein A-I, glycoproteins, and albumin by immunoblotting. With PAGE 2 (10-20% gradient gel), proteins were clearly separated into 11-16 bands with molecular masses of 15,000-150,000 Da; 11 were identified as prealbumin, free kappa and lambda chain, apolipoprotein A-I, glycoproteins, albumin, alpha 1-antitrypsin, transferrin (separated into two bands), immunoglobulin fragments, haptoglobin, and IgG. We analyzed CSF samples collected from 81 patients with cerebrospinal signs by these SDS-PAGE methods and observed prominent bands in some cases.