Urea assay and process and test-kit for determination of urea.

Test means, such as a composition, a test device, method of making a test device and process for detection of urea are disclosed. More particularly, suitable test means are of the type which comprise urease, and a reagent composition comprising acetylacetone and a C1-C4 alkyl aldehyde or the reaction product 3,5-diacetyl-2,6-heptanedione of acetylacetone and formaldehyde. The compositions are advantageously incorporated with a carrier to provide a test device and can be combined in a test kit for determining urea which, in packaged combination, comprises a container of urease, and a container of a reagent according to the invention.