During early embryonic development, the ileum is linked to the umbilicus via the vitelline duct. By the time a human fetus is seven weeks old, the vitelline duct is has completely atrophied. If the duct does not atrophy, a number of medical abnormalities can arise. The most common of these aberrations is Meckel's diverticulum, which occurs when the part of the duct connected to the ileum is retained. About two percent of the population possess this remnant structure, but a much smaller number of people actually develop adverse symptoms related to Meckel’s diverticulum. When symptoms do develop, they may include abdominal pain, blood in the stool, and intestinal bleeding.

In order to localize a green fluorescent tag to filamentous actin in the sample of rat epididymis tissue presented in the digital image above, the specimen was labeled with Alexa Fluor 488 conjugated to phalloidin, a phallotoxin derived from the toxic death cap mushroom. Texas Red conjugated to the lectin wheat germ agglutinin, which selectively binds to N-acetylglucosamine and N-acetylneuraminic residues, was also applied to the tissue sample, as was the DNA probe Hoechst 33342. 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.