Convenient and Effective Method for Removing Fibrinogen from Serum Specimens before Protein Electrophoresis

Abstract

AbstractBackground: Fibrinogen in serum specimens can be misinterpreted on protein electrophoresis as a monoclonal protein. We evaluated selective precipitation of fibrinogen with ethanol.Methods: Pooled human plasma was mixed with absolute ethanol or saline (final concentrations of 40, 80, 100, 120, and 160 mL/L) and incubated at 4 °C overnight or placed in an ice bath for 15 min. After centrifugation, the supernatants and resuspended pellets were used for protein electrophoresis and quantitative measurements of protein and fibrinogen.Results: The fibrinogen band was effectively eliminated from the electrophoretic pattern in the plasma samples treated with ethanol at 100 mL/L and incubated in an ice bath for 15 min without a significant change in immunoglobulin concentrations. The 100 mL/L ethanol did not noticeably change the electrophoretic pattern of monoclonal immunoglobulins. This approach allowed analysis of a sample collected from an arteriovenous shunt kept open with heparin.Conclusions: Ethanol, 100 mL/L, can selectively precipitate fibrinogen without significantly interfering with the immunoglobulins. The precipitation process can be completed in 15 min at 0–4 °C and can avoid the need to obtain another blood sample.