Agarose gel electrophoresis (AGE) and agarose isoelectric focusing (AIEF) were performed on unconcentrated CSF from patients with multiple sclerosis and other neurological disorders. Electrophoretic profiles were examined after staining with silver. Oligoclonal distribution of immunoglobulins were observed in over 90% of patients with clinically definite multiple sclerosis and over half of all patients with possible or probable multiple sclerosis. Up to 20 samples could be simultaneously examined and required the use of only 2-20 microliter of unconcentrated CSF containing 10-100 ng of total IgG. The entire procedure from sample application to completion of staining required less than 3 h. The techniques offered exquisite resolution of abnormal immunoglobulin bands and permitted distinction of normal from abnormal CSF readily.