What type of sample is typically required for a cholesterol test?

A cholesterol test typically requires a serum sample because serum is the liquid component of blood that remains after clotting has occurred. This is essential for accurately measuring cholesterol levels, as the test needs to evaluate the lipids present in the blood without the interference of cells or clotting factors. During the collection process, blood is drawn and allowed to clot, after which the serum is separated through centrifugation.

While whole blood samples can provide some lipid information, serum is specifically preferred in clinical settings for standard cholesterol tests due to its stability and the ability to provide a clearer picture of lipid levels. Each of the other sample types—urine, whole blood, and saliva—are not standard for cholesterol testing, as they do not provide the necessary lipid profile required for an accurate assessment of cholesterol levels.