Thiobarbituric acid is an organic compound and a heterocycle. It is used as a reagent in assaying malondialdehyde (the TBARS assay of lipid peroxidation)., AMDCC Protocols, Animal Models of Diabetic Complications Consortium
It is also used in Kodak Fogging Developer FD-70, part of the Kodak Direct Positive Film Developing Outfit for making black and white slides (positives).
The compound is a sulfur analog of barbituric acid. It can be synthesized by a condensation reaction between thiourea and diethyl malonate.
References