Inflammation of one or both of the epididymides, known as epididymitis, may occur due to an infection of the bladder or urethra that spreads or due to various noninfectious causes, such as the use of certain medications. Among the most common infectious organisms that give rise to epididymitis are Escherichia coli, Chlamydia trachomatis, and Neisseria gonorrhoeae. Symptoms of the condition often include testicular pain and swelling, fever, and painful urination or intercourse. Occasionally there may be abnormal discharge from the urethra or blood in the semen.

The rat epididymis tissue section illustrated in the digital image above was stained with Texas Red conjugated to wheat germ agglutinin, a plant-derived lectin that targets the Golgi apparatus, as well as Alexa Fluor 488 conjugated to phalloidin for cytoskeletal actin. Nuclei were labeled with 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.