Proteins in a sample are separated based on their size by gel electrophoresis. Subsequently, the proteins are transferred to a solid membrane. The membrane is incubated with different antibodies that specifically bind proteins of interest. Fluorochromes attached to the antibodies make it possible to quantify a bound antibody based on fluorescence intensity. The amount of bound antibody depends on the amount of the specific protein in each sample, and comparing fluorescence intensity from the samples yields relative protein levels. At NIOM, we use the Odyssey CLx Infrared Imaging System to develop a digital image and quantify fluorescence from each sample. This technique delivers fast and reproducible results, and the possibility to analyze these right away, without the troubles of film and darkroom.