In order to hold the test tubes in place, a vial tray was designed to keep the tubes upright, as seen in Figure . A PLA ring was added near the base of each tube which allows it to interlock with the holder. This external holder allows for interaction with the cap to each vial, shown in Figure . Once the vials are inserted into the holder, the robot tool rotates counterclockwise and the PLA ring locks into place, enabling robot to remove the TPU corks that seal the tubes so that the material or liquid inside can be tested or replaced.