Testing For The Disease Meat and meat products such as steaks and sausages, or cosmetic products that contain cattle material, are not tested for prion. Presently, the only reliable tissue on which tests for prion can be done is the brain of infected animals. Testing is done during autopsies. It has been found that cooking will not destroy the 'bad' prion protein that is believed to give rise to the disease. The protein can also withstand radiation and autoclaves designed to sterilize surgical instruments.