Kinetic enzymatic determination of creatinine by a rapid semiautomated procedure.

The enzymatic method of creatinine determination, based on the transformation of creatinine to creatine by creatinine amido-hydrolase (EC 3.5.2.10) and subsequent evaluation of the creatinine, has been automated as a kinetic initial rate procedure. This was achieved by using a preincubation period under conditions that reduce the interference by accessory reactions to a very low and constant value, followed by a relatively high concentration of creatinine amido-hydrolase as a starter.