Beta 2 Microglobulin, Urine

Test Codes

EPIC: LAB1232119, Beaker: BETA2MIC U, Quest: 4944

Department

Send Outs

Instructions

For Collection: Void the urinary bladder, then drink a large glass of water. Collect a urine specimen within one hour.

Specimen Collection Criteria

Collect: Random urine specimen in a screw-capped container (preferred) or other sterile collection cup, as described in Instructions. (Minimum: 1.0 mL)

• Pour exactly 10.0 mL of random urine into a Quest Diagnostics Beta-2 Microglobulin Transport Tube (available through Client Supply)
• Alternatively, if the collection tubes are not available, pH the specimen must be adjusted to between 6 and 8 using 1N NaOH prior to shipping.
• Beta-2 Microglobulin in urine is unstable in acidic urine (less than pH 6). Exactly 10.0 mL of urine in the Quest Diagnostics Beta-2 Microglobulin Transport Tube is required to achieve the required pH of between 6 and 8. Any volume above or below 10.0 mL will result in a pH that is outside the acceptable.

Physician Office/Draw Specimen Preparation

Refrigerate (2-8°C or 36-46) prior to transport.

Preparation for Courier Transport

Transport: 10.0 mL urine, refrigerated at (2-8°C or 36-46). (Minimum: 10.0 mL)

Rejection Criteria

Specimens not collected and processed as indicated.

In-Lab Processing

If pH is greater than 8, lower pH to between 6-8 by adding 1M HCl. If pH less than 6, increase pH to 6-8 by adding 5% NaOH. Titrate with appropriate preservative until pH 6-8 has been reached. Please record the pH on the transport tube and test request form.

Transport: 10.0 mL urine, refrigerated at (2-8°C or 36-46) in a plastic transport tube. (Minimum: 10.0 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 5 days
Refrigerated (2-8°C or 36-46°F): 15 hours
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Quest Diagnostics, Wood Dale, IL.

Performed

Monday – Saturday.
Results available in 3-5 days.

Reference Range

<18 Years	Not established
Adults	≤0.20 mg/L

Test Methodology

Immunoturbidimetric

Interpretation

By report.

Clinical Utility

Beta-2-Microglobulin, Urine – Beta-2-Microglobulin (B2M) is a low molecular weight protein that forms the light chain component of the histocompatibility antigen. It is synthesized by all nucleated cell types. It is an integral part of the class I MHC antigens and is present in all body fluids. B2M is filtered through the glomeruli of the kidney and is then reabsorbed and catabolised by the proximal tubular cells. In normal patients only trace amounts of B2M appear in the urine. Elevated urine B2M is seen in tubulo-interstitial disorders. Increased urine B2M is seen in cadmium exposure, diatrizoate, exercise, fever, nephrectomy, semen. There is evidence that monitoring B2M levels in HIV-infected individuals offers an independent predictor of progression to AIDS, leukemia and lymphoma.

CPT Codes

82232

Contacts

Last Updated

12/17/2025