Tech. Sgt. Benjamin McReynolds, 28th Medical Support Squadron laboratory operations NCO in charge, reviews a blood slide under a microscope in the clinical laboratory on Ellsworth Air Force Base, S.D., July 27, 2012. The lab collects and tests biological samples for minor and major health risks to ensure that Airmen stay fit to fight. (U.S. Air Force photo by Airman 1st Class Kate Thornton/Released)