Aflibercept is a recombinant protein composed of the binding domains of two human vascular endothelial growth factor (VEGF) receptors fused with the Fc region of human immunoglobulin gamma 1 (IgG1). Aflibercept, as an ophthalmic agent, is used in the treatment of macular edema following Central Retinal Vein Occlusion (CRVO) and neovascular Age-Related Macular Degeneration (AMD). Compared to other anti-VEGF drugs like bevacizumab and ranibizumab, aflibercept has a higher binding affinity to VEGF-A. BioSim™ Aflibercept ELISA kit has been developed for specific quantification of Aflibercept concentration in human serum or plasma with high sensitivity and reproducibility. Aflibercept ELISA kit is based on the sandwich ELISA principle. Standards and samples (serum or plasma) are added in the microtiter plate coated with the reactant for aflibercept. After incubation, the wells are washed. The HRP conjugated probe is added and binds to aflibercept captured by the reactant on the surface of the wells. Following incubation wells are washed and the bound enzymatic activity is detected by addition of TMB chromogen substrate. Finally, the reaction is terminated with an acidic stop solution. The color developed is proportional to the amount of aflibercept in the sample or standard. Results of samples can be determined directly using the standard curve.