The principle of the method is that the Protazyme AK tablets contain a blue dye-crosslinked with the protease
substrate, casein, which is insoluble in the original form. With the generation of substrate fragments by the enzymatic
hydrolysis, associated part of the dye becomes soluble and the solution becomes blue [14]. The advantage
of this method is the visualization of the hydrolysis by the blue color intensity in the solution. Therefore,
the quantification can be done by using a spectrophotometer in the visible range as well as employing a blue
color intensity pattern kit. It is also possible to compare samples visually without any additional device, only by
the blue color intensity, having qualitative results (Figure 1).
The proteolytic activity visualization in a simple way is very helpful during the use of enzymatic cleaners and
guarantees that the product is working and also it can help in the cleaning validation in the hospital.
In this paper, a reliable method for protease activity quantification is demonstrated using Protazyme AK. This
method proved to be specific, robust and repeatable. Besides that, it can be used as an alternative methodology
of protease activity evaluation in hospitals, contributing with the enzymatic cleaners control and consequently
the sterilization or disinfection efficacy.