Senior Airman Sean McKeel, right, 51st Civil Engineer Squadron readiness and emergency management journeyman, retrieves buffer solution from Staff Sgt. Mark Olsen, 51st Aerospace Medicine Squadron bioenvironmental engineering technician, while checking a dry filter unit during Operational Readiness Exercise Beverly Midnight 13-03 at Osan Air Base, Republic of Korea, Aug. 9, 2013. The solution is used to extract any particles that are in the filter paper for presumptive identification of biological agents. (U.S. Air Force photo/Senior Airman Kristina Overton)