Monoclonal Protein Screen, Random, Urine

Clinical Use

Use

This test is useful for identifying monoclonal gammopathies using random urine specimens. The presence of monoclonal immunoglobulin light chains or quantifiable M-spikes can indicate conditions such as multiple myeloma, primary systemic amyloidosis, light‑chain deposition disease, monoclonal gammopathy of undetermined significance, and idiopathic Bence‑Jones proteinuria. Analysis includes evaluation of urine total protein concentration, electrophoretic pattern, and M‑protein isotype. ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/overview/616915?utm_source=openai))

Special Instructions

Not provided.

Limitations

A random urine specimen is sufficient for screening the presence/absence of monoclonal proteins, but a 24‑hour urine is preferred for quantitation and monitoring. Urine M‑protein MASSFIX alone is not considered adequate screening; reflex to protein electrophoresis is needed if positive. No FDA clearance; developed under CLIA. Hemolysis, radiographic agents, or penicillin can interfere with electrophoresis interpretation. Monoclonal gammopathies are rare in patients <30 years old. ([mayocliniclabs.com](https://www.mayocliniclabs.com/test-catalog/overview/616915?utm_source=openai))

Test Details

Methodology

Mass Spectrometry (MALDI-TOF)

Biomarkers

4 components

M‑protein Mass‑Fix (MPTRU) • MALDI-TOFProtein/Creatinine Ratio (RPTU2) • Clinical ChemistryProtein Electrophoresis (RPEU) • Clinical ChemistryProtein Total and Creatinine components • Clinical Chemistry