Intended use: 5-Fluorouracil Determination Kit is an in vitro diagnostic test for the quantitative detection of 5-Fluorouracil (5-Fu) in human serum and plasma specimen. This product is intended to be used by laboratory professional workers only. This kit is used for auxiliary diagnosis. Results must be combined with clinical observations, patient history, other laboratory parameters, and epidemiological information. 5-Fluorouracil is an antimetabolite drug for the treatment of cancer. It is mainly used for digestive tract cancer and breast cancer. It also has certain curative effects on ovarian cancer and bladder cancer. The drug is highly toxic to normal cells and has many adverse reactions, such as gastrointestinal reactions, bone marrow suppression, alopecia, and ataxia. The monitoring of 5-fluorouracil blood concentration is of great significance for clinical rational drug use and avoiding or reducing adverse reactions.