Which of the following is not a type of support media used for serum protein electrophoresis?

• A. Agarose gel
• B. Cellulose acetate
• C. Acrylamide
• D. Celite

Answer: (D)

Serum protein electrophoresis relies on a solid or semi-solid matrix that provides a continuous porous network for proteins to migrate through under an electric field. The media used to create that network in clinical labs include agarose gels, which form a loose, easy-to-prepare matrix suitable for separating serum proteins, and cellulose acetate, which provides a flat, stable surface that supports rapid separation and clear band visualization. Acrylamide forms a dense polyacrylamide gel that can be used for higher-resolution protein separations in PAGE, though it’s less common for routine SPEP. Celite, on the other hand, is a filtration aid—diatomaceous earth used to clarify solutions or pack chromatography columns. It does not create a continuous medium for proteins to separate in electrophoresis, so it isn’t used as a support medium for serum protein electrophoresis.