Ordering Recommendation

Aid in evaluation and management of multiple myeloma and related plasma cell disorders. Indicated for the diagnosis of patients with oligosecretory or nonsecretory multiple myeloma and light chain amyloidosis.

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum Separator Tube (SST).

Specimen Preparation

Separate from cells ASAP or within 2 hours of collection. Transfer 2 mL serum to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature


Unacceptable Conditions

Plasma. Grossly Hemolyzed and Lipemic Samples


After separation from cells: Ambient: Unacceptable; Refrigerated: 3 weeks; Frozen: 6 months


Quantitative Immunoturbidimetry




1-4 days

Reference Interval

Test Number
Reference Interval
  Lambda Qnt Free Light Chains 5.71-26.30 mg/L
  Kappa Qnt Free Light Chains 3.30 - 19.40 mg/L
  Kappa/Lambda Free Light Chain Ratio 0.26-1.65

Interpretive Data

Undetected antigen excess is a rare event but cannot be excluded. Free light chain results should always be interpreted in conjunction with other clinical and laboratory findings.

Compliance Category



This assay is highly sensitive to increasing concentrations of monoclonal free kappa or free lambda light chains in the serum of patients with evolving or relapsing myelomas.

Hotline History


CPT Codes

83521 x2


Component Test Code* Component Chart Name LOINC
0055168 Kappa Qnt Free Light Chains 36916-5
0055169 Lambda Qnt Free Light Chains 33944-0
0055179 Kappa/Lambda Free Light Chain Ratio 80517-6
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Kappa Qnt Free Light Chains
  • Kappa/Lambda Free Light Chain Ratio
  • Lambda Qnt Free Light Chains
Kappa/Lambda Quantitative Free Light Chains with Ratio, Serum