Apolipoprotein C-III (ApoC3) is a 79 amino acid peptide synthesized in the liver and intestine and bound to the surface of triglyceride rich particles such as very low density lipoprotein and chylomicrons in plasma. ApoC3 controls the triglyceride composition of these particles by inhibiting lipoprotein lipase. ApoC3 loss-of-function mutations have been associated with markedly reduced levels of triglycerides and remnant cholesterol and a decrease in coronary-artery calcification, a surrogate marker for atherosclerosis. Therefore, ApoC3 is a potential new target for reducing residual cardiovascular risk. The sensitive quantitative measurement of total human ApoC3 antigen in plasma, serum, urine & other biological fluid samples is easily performed with this 96 well strip format ELISA kit. The average concentration of ApoC3 in normal human plasma is 0.125 mg/ml. The assay measures total human ApoC3 in the 0.01-5 ng/ml range. Samples giving human ApoC3 levels above 5 ng/ml should be diluted in blocking buffer before use. A 1:200,000 to 1:1,000,000 dilution for normal human plasma is suggested for best results. Human ApoC3 will bind to the affinity purified capture antibody coated on the microtiter plate. After appropriate washing steps, biotinylated primary antibody binds to the captured protein. Excess primary antibody is washed away and bound antibody is reacted with horseradish peroxidase conjugated streptavidin. TMB substrate is used for color development at 450nm. A standard calibration curve is prepared along with the samples to be measured using dilutions of human ApoC3. The amount of color development is proportional to the concentration of total ApoC3 antigen in the sample. All reagents and standards are provided in these ELISA kits.