Apolipoprotein A5 (ApoA5) is fast gaining attention as a key regulator of serum triglyceride concentrations. An ApoA5 mouse knock-out model produced an approximately four fold increase in serum triglycerides, whereas a knock-in model with human ApoA5 produced 50-70% lower concentrations of mouse serum triglycerides. In addition, peroxisome proliferator-activated receptor- agonists, which are used clinically to lower serum triglyceride concentrations, cause increased ApoA5 mRNA expression. Despite these compelling molecular biology data, relatively little is known about ApoA5 protein in human serum. This antibody pair detected recombinant apoa5 protein in sandwich ELISA format and could be potential reagents for the development of clinical diagnostic kits.