Both the samples are added to a gel, which is then filtered through a cartridge. The gel separates the proteins in each sample and the lab looks for oligoclonal banding.
One or less bandings found in the CSF is normal.
Results are considered abnormal if there are 2 or more bandings found in the CSF and not in the blood serum. This may indicate multiple sclerosis (MS). CSF oligoclonal bands are found in 83% to 94% of patients with definite MS. Other causes of oligoclonal banding in CSF include encephalitis, meningitis, Guillain-Barré syndrome, polyneuritis, headache, and other conditions.