Colorectal cancer is one of the most common types of cancer in the United States. Cancers of the rectum account for about 20 percent of all cases of colorectal cancer, making them much less prevalent than cancers of the colon. The vast majority of both types of cancer are adenocarcinomas, which originate in the epithelial cells of glandular tissue. Risk of developing colorectal cancer can be significantly minimized by undergoing regular screenings, which can identify colorectal polyps before their cells have the opportunity to mutate into cancer cells.

In the digital image above, a sample of rat rectum tissue is presented that was labeled with the fluorophore Texas Red conjugated to wheat germ agglutinin, a fluorescent lectin that selectively binds to sialic acid residues. Wheat germ agglutinin conjugates are often used as probes for the Golgi network in mammalian tissues and cells. The sample was also stained with Alexa Fluor 488 conjugated to phalloidin and Hoechst 33342, which target the cytoskeletal filamentous actin network and nuclear DNA, respectively. Images were recorded in grayscale with a 12-bit digital camera coupled to a Nikon Eclipse 80i microscope equipped with bandpass emission fluorescence filter optical blocks. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.