β2-MG

 Method:

Enhanced latex immunoturbidimetric

 

INTENDED USE 

For the in vitro quantitative determination 

of BMG in serum, plasma or urine samples.

 

CLINICAL SIGNIFICANCE
Beta-2-microglobulin (β2-MG) is is expressed by the nucleated cells of the body and on many tumor lines. β2-MG is a low molecular weight protein (MW 11600) consisting of a single polypeptide chain of 99 amino acids. It is filtered out of the body by the kidney glomeruli and almost completely reabsorbed by the kidney proximal tubules. It is found at low levels in the serum and urine of normal individuals. Elevated serum concentrations in the presence of normal glomerular filtration rate suggest increased β2-MG production or release. In patients with rheumatoid arthritis, systemic lupus erythematosus, sarcoidosis and some viral diseases including cytomegalovirus, non-A and non-B hepatitis and infectious mononucleosis, the β2-MG serum level changes in relation to disease activity. Typically only trace amounts of

β2-MG are excreted in the urine and higher rates are interpreted as evidence of tubular dysfunction. Urinary excretion is markedly increased in tubulointerstitial disorders, and where aminoglycosides and anti-inflammatory compounds are present.

 

The Gcell β2-MG Kit provides a sensitive and reliable wide detection range. This assay is for the measurement of

2-microglobulin not only in human serum but also in human urine in just a few minutes.

 

PRINCIPLE
When an antigen-antibody reaction occurs between BMG in a sample and anti-BMG antibody which has been sensitized to latex particles, agglutination results. This agglutination is detected as an absorbance change (570 nm), with the magnitude of the change being proportional to the quantity of BMG in the sample. The actual concentration is then determined by interpolation from a calibration curve prepared from calibrators of known concentration.

 

LINEARITY

The assay range is approximate 0.4 – 60 mg/L for serum and 0.03 – 7.00 mg/L for urine.
If the concentration exceeds the top standard value, dilute the sample 1+1 with 0.9% NaCl. Multiply the result by 2.

It is recommended that results falling below the concentration of the lowest calibrator be reported as less than the concentration of the lowest calibrator.  

 

PROZONE
No prozone Phenomenon occurs when β2-MG ≤ 180 mg/L in
serum and β2-MG ≤ 30 mg/L in urine.

 

INTERFERENCE
No interference is found at concentrations up to:

intralipid ≤ 3%, hemoglobin ≤ 500 mg/dl, Vc ≤ 50 mg/dl, direct bilirubin ≤ 30 mg/dl, RF ≤ 500 IU/ml.

 

SENSITIVITY
The minimum detectable level of BMG with an acceptable level of precision in serum has been determined as 0.13 mg/L. The minimum detectable level of BMG with an acceptable level of precision in urine has been determined as 0.03 mg/L.

 

PRECISION
The CV of the test should be ≤ 5%.