Abstract: Unitary test means, such as a composition or device, purified uricase for use therein, method of making the test device and process for determination of uric acid therewith are disclosed. More particularly, there is provided in test means for the detection of uric acid comprising a uricase-active substance, at least one chromogen, and a peroxidatively active substance, the improvement wherein the uricase active substance is animal-originated uricase which is free of pH sensitive contaminants having a molecular weight of less than about 6000. The test means can take the form of a composition which can further include at least one coupling agent and at least one stabilizing agent. The compositions can optionally be incorporated with a carrier, such as a tablet or matrix, to provide a test device.