We introduce two methods for quantifying and evaluating the amount of surface receptors within a group of cells from fluorescence microscope images. First, the average fluorescence intensity method (AFIM), based on the fluores- cent pixels average intensity, shows interesting properties for quantifying variations of the amount of surface receptors. It however shows an inherent limit coming form pixels saturation. Second, the amount of fluorescent pixels method (AFPM) is based on the amount of fluorescent pixels by modeling its relation with the amount of surface receptors. The established non- linear model is a tool for quantitatively evaluating the amount of receptors. The images used for establishing and developing these methods are originating from a simulated environment. Synthetic images featuring simulated cells with fluorescently- stained surface receptors were used. The two methods have been carefully evaluated based on those synthetic images.