Abstract: A method of visualizing biological material on medical instruments is disclosed which consists of the steps of selecting a dye material capable of creating fluorescence or phosphorescence when applied to biological material and subjected to ultraviolet light; applying the dye to a medical instrument; mounting the medical instrument in a viewing box; exposing the medical instrument in the viewing box to ultraviolet light and observing the instrument through an opening in the view box to determine if the dye has caused fluorescence or phosphorescence of material on the instrument indicative of the presence of biological material thereon.