--the much more detailed and specific test fro this is an immunofixation electrophoresis of serum and urine.

In fact, Dr. Latov's clinical application paper for Quest Diagnostics (which we have posted in the Useful Websites section here) indicates it is the preferred test, as a small spike may be obscured in a serum protein electrophoresis.

The immunofixation electrophoresis is normally done with an enumeration of classes of immunoglobulins simply to see their numerical levels, as well as a breakdown of types. What is looked for are monoclonal antibodies or M-proteins, which can be associated with neuropathy and a whole host of other conditions, most notably blood disorders.