An automatic sample tube cleaner was designed and fabricated. Quick- connecting devices for the tubes and solenoid-operated air valves for all services are employed. The solenoids are actuated by an electrical timing mechanism which schedules steam, cleaning agent, hot water, air, and vacuum into the tube rack. With this apparatus it is possible to clean 48 tubes in the same time as was required for 13 tubes on the manually operated system. This results in a saving of one-half mmn-day per day and a more uniform, controlled cleaning method. (auth)