Why the test is performed:
This test helps confirm the diagnosis of multiple sclerosis (MS).
The laboratory procedure is called CSF electrophoresis, which is a method used to study the levels of protein in the cerebrospinal fluid (CSF).
In electrophoresis, a CSF sample is applied to a gel (solid medium allowing the movement of proteins), and a voltage is applied. The proteins migrate along the gel based on their charge (roughly on their size). The gel is stained, and significant amounts of similar proteins will cause a visible "band" to be present. The term oligoclonal bands refers the presence in CSF of two or more protein bands of a specific immunoglobin (IgG) that have greater intensity than in the concurrent serum sample. This pattern of banding is seen in patients with MS, and other conditions.