Analysis of Bence Jones proteinuria by high resolution two‐dimensional electrophoresis

Abstract
Analysis of Bence Jones proteinuria by high resolution two‐dimensional electrophoresis (2‐DE) and immunoblotting reveals a complex pattern of light chain (LC) isoforms corresponding to the free monoclonal Bence Jones protein and its fragments. Replica blotting gives duplicate blots for LC typing (λ, ϰ) and, under the conditions employed, leaves sufficient protein for Coomassie Blue staining of the urinary protein profile and pI/Mr determination of the LC isoforms. Carrier ampholytes (CAs, in our “simplified” 2‐DE system) and immobilised pH gradients (IPGs, in the Multiphor 2‐DE system) give similar LC isoform patterns. Artifacts, including cone‐like distortions and trailing “piggyback” spots, are visualised with both 2‐DE systems. IPGs are advantageous as they allow reproducible detection of strongly basic LC isoforms by isoelectric focusing (under equilibrium conditions) without recourse to CA nonequilibrium pH gradient electrophoresis.