1.1. Serum and Plasma
In vitro assay for the quantitative determination of β2-microglobulin (B2M) in human serum as well as EDTA, citrated, and heparinised human plasma. The test has to be performed on the LIAISON® Analyzer family.
1.2. Urine
The use of urine samples is also possible. For this purpose “B2MU” has to be selected in the Sample Loading Dialogue (instead of “B2MS”). Never start “B2MU” with serum or plasma samples! The selection of “B2MU” increases automatically the sample volume pipetted to 100 μL. The calibrator volumes and other characteristics of the reaction remain unaffected, the concentrations are still expressed as mg/L. Integral calibration is always performed by the “B2MS” procedure; adaptation of result output for “B2MU” occurs automatically, if selected.
Spontaneous urine which has been adjusted to pH 6-8 with 0.5 M NaOH solution immediately after collection should be used for the determination within 24 hours; for longer storage the specimens should be frozen at-20 °C.
A preliminary upper reference range for β2-microglobulin in urine obtained by this method has been estimated to 0.3 mg/L on a basis of 127 apparently normal probands (female and male). Each laboratory should establish its own reference range.