Abstract: Test means, such as a composition or a test device incorporating the composition, method of making the test device and process for determination of creatinine using the test means are disclosed. More particularly, creatinine is measured by incubating with a test means, such as a composition, comprising a creatinine hydrolyzing enzyme, creatine amidinohydrolase, sarcosine dehydrogenase and a tetrazolium indicator and observing any resultant color change. A colored formazan is produced in proporation to the creatinine present. The sensitivity of the system is increased and the detection limit lowered by including formaldehyde dehydrogenase, diaphorase and nicotinamide adenine dinucleotide (NAD). Creatine or sarcosine are measured in this system by omitting the creatinine hydrolyzing enzyme or the creatinine hydrolyzing enzyme and the creatine amidinohydrolase, respectively, from the composition used in testing for creatinine.

Abstract: The present invention relates to compositions and methods for use in determining free and total cholesterol levels in fluids such as body fluids. A test for free cholesterol is disclosed based on the determination of hydrogen peroxide released through the action of a chemical system having cholesterol oxidase activity on free cholesterol. A preferred means for determining the released hydrogen peroxide involves the use of a substance having peroxidative activity and an oxidation-reduction indicator. The addition of a chemical system having cholesterol ester hydrolase activity to the free cholesterol test composition provides an integral test composition for the determination of total cholesterol.