Test Directory

Beta-2-Microglobulin (B2M) is a low-molecular weight protein found on the cell surfaces of all nucleated cells and shed into the blood, particularly by tumor cells and lymphocytes. Due to its small size, it passes through the glomerular membrane, but normally less than 1% is excreted due to absorption in the proximal tubules of the kidney. Therefore, high plasma levels of B2M occur in renal failure, inflammation, and neoplasms, especially those associated with B-lymphocytes. It’s particularly useful in monitoring kidney transplant recipients.

Preferred Specimen Type: Serum

Desired Specimen Volume: 2 mL

Preferred Collection Container: Gold Top, Serum Separator

Separator tubes: Contains clot activator and gel for separating serum from cells, but not anticoagulant. Separate serum from cells as soon as the clot has formed (30 minutes). If specimen is centrifuged before clotting is complete, a fibrin clot will form on top of the cell. This may cause the gel barrier to not be intact and could cause improper separation of serum and cells, possibly affecting test results.

Transport refrigerated.

1.6-4.0 mg/L