DefinitionApolipoprotein CII (apoCII) is a protein found in large fat particles absorbed from the gastrointestinal tract. It is also found in very low density lipoprotein (VLDL), which is made up of mostly triglycerides.This article discusses the test used to check for apoCII in a sample of your blood.Alternative NamesApoCII; Apoprotein CII; ApoC2How the test is performedBlood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to t