Enzymatic assay design for creatinine varies between manufacturers but commonly employs the enzyme creatininase coupled with a chromogen that reacts with hydrogen peroxide to form a product that can be quantified (Clarke, 2016). Enzymatic assays tend to be less sensitive to interference than the Jaffe reaction; however, interferents still exist that can influence assay performance. For example, bilirubin or ascorbate may interfere due to their ability to react with hydrogen peroxide, artificially decreasing its concentration (as a reporter molecule in the reaction) after the assay has completed.
