Serum Free Kappa and Lambda Light Chains (SFLC)

Serum capillary electrophoresis may not detect all paraproteins due to factors like low concentration, inadequate electrophoretic separation or being present only in urine. In such instances quantifying serum free kappa and lambda light chains, calculating the κ:λ ratio and urine protein electrophoresis may help identify monoclonal proteins. The κ:λ ratio may be abnormal in amyloidosis, light chain disease and in impaired renal function.