A Comparison of gel (Hydragel 30) and capillary (Capillarys III Tera) electrophoresis for the characterization of human serum proteins

Abstract

ObjectivesTo compare gel (Hydrasys 2 from Sebia) and capillary (Capillarys III Tera, Sebia) electrophoresis for the characterization of human serum proteins. Design and methods304 sera tested by gel electrophoresis during 8 routine laboratory days were concurrently tested by capillary electrophoresis. Gels were read by an experienced medical technologist while capillary profiles by a Sebia representative and the same technologist. Most sera (214 of 304, 70%) were also analyzed by immunofixation electrophoresis, used here as the gold standard to calculate sensitivity and specificity of the gel and capillary systems. ResultsGel and capillary estimated the concentration of albumin, gamma region, and M-spikes nearly perfectly, and that of beta, alpha-2, and alpha-1 regions with excellent correlation. The two systems classified concordantly 268 of 304 sera (88% agreement) as having no, one, or two M-spikes, but differed in the remaining 36 sera (12%). Gel electrophoresis correctly identified M-spikes in 82 of 112 sera that were shown to have monoclonal band(s) by immunofixation (73% sensitivity), and correctly did not reveal M-spikes in 97 of the 102 sera that had no immunofixation bands (95% specificity). Capillary achieved slightly higher sensitivity (85 of 112, 76%) and slightly lower specificity (94 of 102, 92%), but the two areas under the ROC curves were nearly identical at 0.84. ConclusionsGel and capillary electrophoresis systems perform similarly to estimate the concentration of serum protein fractions and detect M-spikes.