Kappa and Lambda Free Light Chains, Serum 
Mnemonic LIGHT CHAINS
CPT 83883
Test Code 1003775
Synonyms  
Test Includes Kappa free light chains, Lambda free light chains, Kappa/Lambda free light chain ratio 
Specimen Serum
Volume 1.0 mL
Container SST or Red Top Tube
Special Instructions  
Specimen Prep Centrifuge* For Red Top only, transfer serum to Plastic Transport Tube
Storage Refrigerate
Transport Temp Refrigerated
Stability Rm Temp 8 hours, Separate serum and cells as soon as possible to avoid hemolysis
Stability Refrig 14 days
Stability Frozen 1 month. Repeated freeze/thaw cycles should be avoided.
Methodology Nephelometry
Rejection Criteria Lipemic or hemolyzed specimens 
Reference Value Kappa free light chains: 3.30 - 19.40 mg/L; Lambda free light chains: 5.71 - 26.30 mg/L; Kappa/Lambda free light chain ratio: 0.26 - 1.65 
Performed/TAT     3 days maximum    
Comments The Freelight assay system detects and quantitates free immunoglobulin light chains, without interference by whole immunoglobulins. Published studies have shown that serum free light chain detection is more sensitive than urinary assays for identifying multiple myeloma and related B-lineage tumors. Diagnosis cannot be made and treatment must not be given on the basis of free light chain measurement alone. Clinical history and other laboratory findings must be taken into account.