Serum proteins can be separated in an electric field, in which most proteins (being negatively charged) migrate toward the positive electrode. Such an electrophoretic pattern is shown in the stained strip at the bottom. Such a strip can be scanned to yield the pattern seen above, and the relative quantities of the various fractions determined. In this example of a normal human serum, the protein in the gamma-globulin peak (which is characteristically broad) is determined to be at a concentration of 1.39 grams per deciliter, constituting 18.8% of total serum protein.