Background: Treatment of serum with ethanol at 100 ml/l eliminating fibrinogen from electrophoretic pattern produces an additional band at α2/β junction. This study is to determine the source and the nature of this artifact. Methods: The supernatant after ethanol precipitation was used for electrophoresis. Protein concentrations of each fraction in ethanol- and saline-treated samples were compared, and immunofixation electrophoresis (IFE) to identify transferrin, C3, and LDL was performed. C3 IFE was also conducted for fresh sera and sera stored for 2 weeks. Results: The artificial band at α2/β junction was identified in ethanol-treated sera but not in saline-treated sera. Protein concentration in the β fraction was reduced after ethanol treatment as compared to saline-treated samples (n = 10, p < 0.01). The spurious band at α2/β junction was recognized in C3 IFE. C3 IFE also showed a band at α2/β junction in samples stored for 2 weeks. Conclusions: Ethanol treatment of serum creates an artificial band with C3 immunoreactivity at α2/β junction. This could be due to the accelerated hydrolysis of C3 by ethanol treatment. Laboratories using ethanol to evaluate a possible fibrinogen band should be aware of this phenomenon, and the serum protein electrophoretic pattern after ethanol treatment should only be used to rule out fibrinogen.
All Science Journal Classification (ASJC) codes
- Clinical Biochemistry
- Biochemistry, medical