The confocal laser scanning microscope (CLSM) has been used by scientists to visualize three-dimensional (3D) biological samples. Although this system involves lasers, electronics, optics, and microscopes, there are few published tests that can be used to assess the performance of this equipment. Usually the CLSM is assessed by subjectively evaluating a biological/histological test slide for image quality. Although there is a use for the test slide, there are many other components in the CLSM that need to be assessed. It would be useful if tests existed that produced reference values for machine performance. The aim of this research was to develop quality assurance tests to ensure that the CLSM was stable while delivering reproducible intensity measurements with excellent image quality.