ABSTRACT
As with any clinical laboratory method, control serum samples must be run daily. Commercially available lyophilized controls are convenient and ensure adequate migration of the sample. Note that C3 may not provide a discrete band in some lyophilized preparations, altering the appearance of the b-region. Densitometric scanning or electropherograms (for capillary zone electrophoresis) of control serum provide objective criteria to determine whether the percentage of the major bands is within an acceptable range. Although some laboratories interpret gel-based serum protein electrophoresis without densitometric scanning, the information available from densitometry is useful in quality control, confirming impressions from direct visual examination of the gel and following patients with monoclonal gammopathies (Mproteins).1 Below is a brief list of the approaches I recommend when interpreting protein electrophoretic patterns.
