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. BioVision’s BioSim™ anti- Aflibercept ELISA kit is designed to detect antibody against Aflibercept with high specificity and sensitivity in serum and plasma samples. anti-Aflibercept ELISA is based on the sandwich ELISA principle. Controls and samples are incubated in the microtiter plate coated with the drug aflibercept. After incubation, the wells are washed. Then, HRP conjugated probe is added and binds to aflibercept antibodies captured by the drug aflibercept on the surface of the wells. Following incubation wells are washed and the bound enzymatic activity is detected by addition of chromogen-substrate. Finally, the reaction is terminated with an acidic stop solution. The color developed is proportional to the amount of aflibercept antibodies in the sample or controls. The results can be evaluated with using cut-off value.