Analysis and general classification of serum cryoglobulins by capillary zone electrophoresis

Abstract

The analysis and general classification of serum cryoglobulins (CG) by capillary zone electrophoresis (CZE) are described. This technique allowed the introduction of several new aspects to the analysis of CG: (i) direct detection of monoclonality of the gamma-globulins and general classification of the different CG types, (ii) a tenfold decrease in sample size, (iii) direct quantification of the cryoprecipitate without the need for further chemical analysis, and (iv) mathematical correction for the coprecipitation to avoid extensive washing steps or falsely elevated results. In addition to that, since staining steps are avoided, the method is rapid and easy to perform. The method has the limitation of not being able to perform immunological characterization directly of the CG. One hundred and ninety-eight samples were analyzed by this technique. Many of the cryoprecipitates have a higher ratio of gamma-globulins/albumin when analyzed by CZE compared to analysis by agarose electrophoresis. Clinical examples are presented to illustrate the advantages of this method for the analysis of serum cryoglobulins.

How I treat cryoglobulinemia

“…66,67 The prevalence of circulating cryoglobulins in the HCV-infected population is close to 50%, 68 but only 15% of people in that group show clinical signs of cryoglobulinemia. 69 The prevalence of circulating cryoglobulins in hematologic and rheumatologic diseases is likely underreported.…”

Fenofibrate and fenofibric acid analysis by capillary electrophoresis

“…The acetonitrile performs the function of a terminating ion in eliciting the needed high field strength without being one [12]. The borate buffer was chosen because it is a general buffer used for separating proteins as well as other compounds in our lab [14]. Fenofibric acid compound migrates in the borate-carbonate buffer at about 6.5 min while the internal standard migrates ahead at about 5.5 min (Fig.…”

“…CZE for fenofibric acid: 7 g boric acid, 7 g sodium carbon-ate (Mallinckrodt, St. Louis, MO, USA) and 5 g/L polyethylene glycol 6000 (Fisher Scientific, Fair Lawn, NJ, USA) were used for the CZE analysis [14].…”

Analysis of immune complexes by capillary electrophoresis

“…For the electrophoretic separation, a buffer similar to that used previously for separating serum proteins was chosen [17]. This buffer gives good and rapid separation for immunoglobulins separating them from other serum proteins in less than 6 min and reveals the presence of monoclonal bands.…”

“…The electrophoresis buffer was composed of 5 g boric aid, 5 g sodium carbonate and 0.3 g PEG dissolved in 100 mL water, pH 8.9 [17]. The PEG buffer consisted of PEG (2.2%) in phosphate buffer, 10 mmol/L, pH 7.1 containing 0.5% sodium chloride, stored at 0-47C.…”