Globulin

Globulin is one of the three types of serum proteins, the others being albumin and fibrinogen. Some globulins are produced in the liver, while others are made by the immune system. The term globulin encompasses a heterogeneous group of proteins with typical high molecular weight, and both solubility and electrophoretic migration rates lower than for albumin. The normal concentration in blood is 2.2 to 3.9 g/dl.

It is sometimes used synonymously with globular protein. However, albumin is also a globular protein, but not a globulin. All other serum globular proteins are globulins.

Protein electrophoresis is used to categorize globulins into the following four categories:
 * Alpha 1 globulins
 * Alpha 2 globulins
 * Beta globulins
 * Gamma globulins (one group of gamma globulins are immunoglobulins, that function as antibodies)



Pseudoglobulins and euglobulins
Pseudoglobulins are a fraction of globulins that are soluble in ammonium sulfate solution more so than the euglobulin fraction. Pseudoglobulins are soluble in pure water, whereas euglobulins are insoluble under the same circumstances.