Beta-2 globulin %
What it measures, and what changes the number.
Beta-2 globulin % comes from serum protein electrophoresis, a test that separates blood proteins into bands by how they move in an electric field. The beta-2 band is made up mostly of complement C3, a protein of the immune system, with smaller contributions from other proteins. This line shows that band as a share of all protein in the sample.
It is read together with the other electrophoresis fractions and with total protein, since each percentage only makes sense next to the rest of the pattern and next to the absolute amount of protein.
The method matters. Capillary and agarose gel electrophoresis split the beta region differently, and some labs report a single beta fraction instead of two. If plasma is used instead of serum, fibrinogen can appear near this band. Labs may print it as Beta 2 globulinas %.
Often read alongside: Beta-2 globulin, Beta-1 globulin %, Albumin %, Gamma globulin %, Total protein