A Serum Protein Electrophoresis (SPEP) is not the current gold standard test of choice for determining if there are rogue monoclonal antibodies (M-proteins) in the blood (which can be associated with amylidosis and other blood disorders.

The more specific Immunofixation electrophoresis of serum and urine should be ordered--this is normally done with an Ig subclass enumeration as well, to see if there are more antibodies than there should be. They wil look for specific bands that may indicate the rogue antibodies and the protein subclasses characteristic of the condition.

An SPEP is not sufficient, as small elevations in the Ig subclasses can be obscured in the overall gamm globulin testing.

See:

http://neuromuscular.wustl.edu/antibody/mprotein.htm

http://neuromuscular.wustl.edu/nother/amyloid.htm

http://www.questdiagnostics.com/hcp/...eralNeurop.htm