ABSTRACT
A selected group of 308 sera were analyzed by capillary electrophoresis (CE), agarose gel electrophoresis (AGE), and cellulose acetate electrophoresis (CAE) and evaluated for abnormalities that would suggest the presence of a monoclonal protein. The sensitivity (an electrophoretic abnormality in sera that contained a monoclonal protein) and specificity (a normal electrophoretic pattern in sera that did not contain a monoclonal protein) was determined for each electrophoretic procedure. CAE was the most specific procedure and CE was the most sensitive. The increase in sensitivity of CE was primarily due to increased detection of cryoglobulins and free light chains. The quantitation of the gamma region and/or monoclonal antibody peaks by CE was similar to results obtained by AGE. Quantitation of very large monoclonal protein peaks (> 3.0 g/dL) by on-line absorption detection (CE) yielded higher results than quantitation by dye-binding (AGE).
Subject(s)
Blood Proteins/analysis , Electrophoresis, Agar Gel/methods , Electrophoresis, Capillary/methods , Electrophoresis, Cellulose Acetate/methods , Acetic Acid/chemistry , Adult , Aged , Female , Humans , Male , Middle Aged , Normal Distribution , Sensitivity and Specificity , Sepharose/chemistryABSTRACT
This study details the qualitative results from a comparative evaluation of agarose gel electrophoresis (AGE) and (CZE) as a screening procedure for monoclonal proteins in serum. Three hundred and five serum samples were analyzed by the two techniques; samples suspected of containing monoclonal proteins based on abnormalities observed with AGE or CZE were confirmed by immunoelectrophoresis and/or immunofixation. CZE separation conditions were simple (requiring only a bare silica capillary and 150 mM borate buffer, pH 10.0) and separation was complete in under 120 s. The results obtained by CZE were comparable or better than those obtained with AGE. Samples displaying "point-of-application" artifacts on AGE were not problematic by CZE analysis; an abnormal profile, due to the presence of a monoclonal protein, or a normal profile were clearly observable. The rapid analysis, excellent reproducibility, automation and relatively high throughput (approximately 90 samples per 8 h on a single instrument) sets the stage for CZE analysis of serum proteins to be used routinely in a clinical setting.
