What laboratory test is used to separate blood proteins based on their electrical charge?

Serum protein electrophoresis is the correct choice because it is a laboratory method specifically designed to separate proteins in serum based on their electrical charge. During this process, a sample of serum is placed on a support medium and an electrical current is applied. Proteins in the serum carry different charges and therefore migrate at different rates; this separation allows for the analysis of various protein fractions, such as albumin and globulins.

This method is particularly important in diagnosing and monitoring conditions that affect protein levels in the blood, like multiple myeloma or liver diseases, by providing a visual representation of the protein composition. The results can reveal abnormalities in protein concentration and types, aiding clinicians in making informed medical decisions.

In contrast, alternatives like a complete blood count primarily measure red and white blood cells alongside platelets, rather than specifically separating proteins. A Western blot is primarily used for the detection of specific proteins and involves a different methodology involving gel electrophoresis followed by transfer and restriction with antibodies. Urinalysis examines urine for various components, often focusing on metabolic waste and organic compounds, thus is not related to the separation of blood proteins.