Abstract
The quantitation of cholesterol in lipoprotein subfractions is valuable in estimating the risk for coronary artery disease, but requires multiple tests. We describe a relatively simple procedure, referred to as the dual HDL/total cholesterol (DHT) assay, which allows the sequential measurement of HDL cholesterol (HDL-C) and total cholesterol (total-C) in a single tube. HDL-C is first measured using a homogeneous assay that utilizes an anti-apolipoprotein B [apo(B)] antibody, which sterically blocks the enzymatic measurement of cholesterol on the non-HDL subfractions. Next, deoxycholate is added, which disrupts the antibody-apo(B) complex and allows the subsequent enzymatic measurement of the remaining cholesterol in the non-HDL subfractions. The DHT assay has an acceptable analytical performance and yields results similar to standard methods: for HDL-C, γ(DHT) = 0·98x+0·19, r = 0·90; for total-C, γ(DHT) = 1·11x–0·09, r = 0·99. In summary, the DHT assay is a homogeneous assay for both HDL-C and total-C, and provides a simple and cost-effective method for screening for hyperlipidaemia.