A device for automation of biological and medical tests wherein test subjects or specimens that are placed in test vessels are subsequently treated by different liquid reagents, including: at least two test vessels of dimensions providing accommodation of specimens, a hydraulic gravity feeding system to deliver the liquid reagents into the two test vessels, a hydraulic gravity discharging system to remove waste liquid or spent reagents from the test vessels and directing them into an apparatus for accommodation of the such waste liquid or spent reagents, and a control system operating the device. A mechanical system is provided for agitating the test vessels.