In the Oliver-Rosalki method, what type of reaction is used to measure creatine kinase (CK) activity?

The Oliver-Rosalki method for measuring creatine kinase (CK) activity involves a reverse reaction approach. In this method, the enzyme creatine kinase catalyzes the reversible phosphorylation of creatine to form phosphocreatine and ADP from ATP. The reaction allows for the quantification of CK activity by measuring the amount of ADP produced in the reaction, which can then be read spectrophotometrically.

Using a reverse reaction is particularly advantageous in this context because it allows for the monitoring of the conversion of substrates to products in a scenario where the concentration of the products (ADP and phosphocreatine) can be effectively measured. This approach enhances sensitivity and precision in the determination of enzymatic activity compared to some forward reaction methods.

In summary, employing a reverse reaction is critical to the Oliver-Rosalki method as it facilitates the accurate measurement of CK activity, aligning with the method's design to optimize detection of enzymatic reactions.