Fig. 2.

Representative gels from FLC-Modified SIFE are presented. The lanes marked SP, G. A, M, κ, λ, represent conventional serum immunofixation gels stained with appropriate antisera. The lanes marked anti-free k and anti-free λ represent FLC-Modified SIFE, stained with antisera to respective free light chains. In FLC-Modified SIFE, undiluted patient serum was applied and following staining with respective antisera, the gels were washed three times.

The lane marked anti-free k shows free monoclonal light chains in the same location as the intact immunoglobulin (Left half of figure). Please note that in the lane stained with anti-free kappa undiluted serum was applied, whereas in conventional SIFE G and K lanes were at 1:10 dilution of serum. The broader band in the anti-free kappa lane represents the higher dose of inoculum. In the right half, conventional SIFE shows monoclonal IgG λ and free monoclonal λ light chains in a separate anodal band. Only the monoclonal λ light chain band is stained with the antiserum to free λ light chains.