What is VAP? VAP (Vertical Auto Profile) is one of the brand names given to a commercial, proprietary method for testing lipoproteins in blood. It is possible to separate out the different sizes of lipoprotein molecules by density (through centrifugation), such as with the VAP test, or by size and electrical charge (through electrophoresis). Patients with a higher percentage of small, dense LDL molecules are believed to be at greater risk for atherosclerosis than those with a higher percentage of large LDL. However, the data are not clear on the clinical usefulness of these tests.