Immunoglobulin Total Light Chains, Urine
Use
This test is useful for monitoring patients whose urine demonstrates large M‑spikes, confirming the quantitation of specimens that show M‑spikes by electrophoresis, and detecting urine monoclonal proteins to identify specimens that need urine protein electrophoresis. It serves as a quantitative complement to urine M‑spike quantitation by electrophoresis, especially valuable in patients with light‑chain multiple myeloma when serum M‑spikes are small or absent.([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/overview/87934?utm_source=openai))
Special Instructions
If serum is being submitted on the same patient for FLCS / Immunoglobulin Free Light Chains, Serum, that test should be ordered under a different order number.([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/overview/87934?utm_source=openai))
Limitations
Unlike electrophoretic M‑spikes, this immunonephelometry‑based assay quantifies both polyclonal and monoclonal light chains and is therefore not sensitive for detecting small monoclonal abnormalities. A normal kappa/lambda ratio does not rule out a monoclonal protein, and an abnormal ratio does not identify one. Urine protein electrophoresis and isotype testing are more sensitive and specific. Also, quantitative urine kappa by immunonephelometry yields results approximately twice those from electrophoresis M‑spike measurements; sequential results should be compared using consistent methodology.([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/overview/87934?utm_source=openai))
New York Approved
Methodology
Immunoassay (Nephelometry)
Biomarkers
Result Turnaround Time
0-3 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
1 mL
Minimum Volume
0.5 mL
Container
Plastic, 5‑mL tube
Collection Instructions
Collect either a random urine specimen (refrigerate after collection and send refrigerated) or a 24‑hour urine (no additive needed; urine may be kept ambient during collection but should be refrigerated within 4 hours of completion).
Causes for Rejection
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 7 days |
| Frozen | 20 days |