Development and application of a new colorimetric urease activity determination method using camera

The methods used to measure the bioactivities of synthetic and natural compounds and mixtures are important tools in investigating their usability for various purposes. Today, new approaches and methods have been developed and applied in determining many bioactivities such as antioxidants and enzyme inhibition. In order to make spectrophotometric measurement methods practical, new colorimetric approaches that eliminate the need for a spectrophotometer device are being developed and applied. In this doctoral thesis, a new colorimetric urease activity determination method based on an approach existing in the literature with the use of phenol red has been developed, its validation and application to natural and synthetic samples for the purpose of inhibition measurement have been carried out. The developed method has been optimized in terms of parameters such as plate, light brightness, temperature, plate-camera distance, and the method has been validated. In the validated method, the ideal environment and conditions have been determined as 25oC in a box, light source at 0 cm and brightness at 60%, plate-camera distance at 25 cm and using a flat bottom plate. With the newly developed colorimetric method, the % inhibition values of green tea extract and 2 synthetic compounds were successfully determined in comparison with the spectrophotometric method