The s LDL-EX “SEIKEN” assay quantitatively determines small, dense low-dense lipoproteins (sdLDL), a subfraction of LDL associated with an increased risk for cardiovascular disease (CVD). Past studies have shown that people with a predominance of sdLDL (so called Pattern B patients) have a 3-fold increased risk of myocardial infarction (MI), while the relative risk is 4.5 for coronary artery diseases (CAD) and 7 for MI when sdLDL levels are greater than 100mg/dL. Recent studies have also shown that a predominance of sdLDL is a strong and independent risk factor of coronary heart diseases (CHD) and that there is a clear relationship between its levels and the severity of the diseases. Furthermore, the s LDL-EX assay has a good opportunity for standardization compared to current methods, which are disparate and require considerable technical expertise to perform. The patented assay consists of two steps: the first removes chylomicrons, VLDL, IDL, large LDL, and HDL using a surfactant and sphingomyelinase, and in the second step, a specific surfactant releases cholesterol only from the small, dense LDL particles for measurement by standard methods. The test can be run on any standard clinical chemistry analyzer and gives results within 10 minutes.