The above video demonstrates how to extract the chemical fluorescein from highlighter markers using no other chemical besides common rubbing alcohol. As is demonstrated in the video, fluorescein is spectacular to watch dissolve into water, especially under black light. Below is a list of other excellent videos that feature fluorescein.
Dr. Nozman's demonstrations (subtitled in English):
NurdRage (An excellent tutorial to make Fluorescein in the lab):
In addition to the above videos here are several links describing the process by which Fluorescein is used to detect trace amounts of blood: