Staff Sgt. Johnathon Barton, the 28th Medical Support Squadron noncommissioned officer in charge of central operations, explains how to properly insert a needle to take blood during a training exercise at the 28th Medical Group laboratory at Ellsworth Air Force Base, S.D., Dec. 4, 2018. Phlebotomists-in-training can intern at the base clinic to get hands on experience for their degree. (U.S. Air Force photo by Airman 1st Class Nicolas Z. Erwin)