6-Thiopurine (6TP) is an anti-cancer chemotherapy drug used mainly for a childhood leukemia called acute lymphoblastic leukemia (ALL) as well as some autoimmune disorders. This chemotherapy drug is used to help in the cure of acute lymphoblastic leukemia (ALL), an anti-inflammatory drug, and an immunosuppressant in organ transplants. Small doses of 6-thiopurine can have serious side effects such as a dearth in red and white blood cells and any level of liver damage. To prevent any serious damages from occurring in a patient’s body, regular blood monitoring is required. However, the current methods used to detect 6-thiopurine are not competent for use in detecting small quantities of 6-thiopurine leaving patients in more pain. In order to detect these small amounts, the sample must go through chromatography for separation and purification as well as Nuclear Magnetic Resonance Spectroscopy (NMR) and Infrared Spectroscopy (IR) to find out the molecular structure of the sample. Finally, the sample will go through fluorescence spectroscopy to detect even a small concentration (~100fM) of 6-thiopurine in the sample. Added to the 6-thiopurine is 9-(chloromethyl)anthracene because 6TP isn’t actually detected by the fluorometer but 9-(chloromethyl)anthracene therefore by reacting the two products (and removing the excess product), it can be detected the concentration of 6-thiopurine.