Researcher pipettes blood samples (IMAGE) Experimental Biology Caption A researcher pipettes blood samples to measure markers of autophagy, a defense mechanism cells use to protect themselves from damage. Credit James McCormick, University of Ottawa. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.