A variety of bacteria are necessary for the colon to function properly, and antibiotic treatments can sometimes cause colon problems due to the elimination of such bacteria. Lack of sufficient dietary fiber has been linked to colon malfunction and disease as well, studies indicating that fiber is essential as food for the good bacteria that inhabit large intestine. Without enough fiber in the diet, the good bacteria are unable to survive, producing a void that can be inhabited by pathogens. Some of the many diseases that may affect the colon include colitis, Crohn’s disease, irritable bowel syndrome, polyposis, and cancer. Colon cancer is the second most commonly diagnosed cancer among Americans, but it has an excellent cure rate.

The sample of rat colon tissue presented in the digital image above was labeled with Texas Red conjugated to wheat germ agglutinin, a lectin that selectively binds N-acetylglucosamine and sialic acid residues. The specimen was also labeled with Alexa Fluor 488 conjugated to phalloidin and Hoechst 33342, targeting F-actin 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.