A gripper apparatus, comprising: a gripper component including a first and second moveable jaws (128A, 128B) arranged alongside of a gripper axis; a first pair of opposed fingers (134A, 134B) that are positioned in an opposed orientation across the gripper axis, including: a first finger coupled to the first moveable jaw; and a second finger coupled to the second moveable jaw, the first and second fingers being adapted to grip a sample container, the sample container including a tube body and a cap; and a seating member positioned adjacent to the first and second fingers and moveable along the gripper axis, the seating member being adapted to contact the cap of the sample container when the first and second fingers are in an opened configuration; characterized in that the gripper apparatus further comprises a linear motion producer coupled to the seating member and configured to provide controlled linear motion to drive the seating member along the gripper axis; and a seating member position controller electrically coupled to the linear motion producer and adapted to drive the seating member to any preprogrammed extension or retraction position alongside the first and second fingers. a gripper component including a first and second moveable jaws (128A, 128B) arranged alongside of a gripper axis; a first pair of opposed fingers (134A, 134B) that are positioned in an opposed orientation across the gripper axis, including: a first finger coupled to the first moveable jaw; and a second finger coupled to the second moveable jaw, the first and second fingers being adapted to grip a sample container, the sample container including a tube body and a cap; and a seating member positioned adjacent to the first and second fingers and moveable along the gripper axis, the seating member being adapted to contact the cap of the sample container when the first and second fingers are in an opened configuration; characterized in that the gripper apparatus further comprises a linear motion producer coupled to the seating member and configured to provide controlled linear motion to drive the seating member along the gripper axis; and a seating member position controller electrically coupled to the linear motion producer and adapted to drive the seating member to any preprogrammed extension or retraction position alongside the first and second fingers. a first finger coupled to the first moveable jaw; and a second finger coupled to the second moveable jaw, the first and second fingers being adapted to grip a sample container, the sample container including a tube body and a cap; and a seating member positioned adjacent to the first and second fingers and moveable along the gripper axis, the seating member being adapted to contact the cap of the sample container when the first and second fingers are in an opened configuration; characterized in that the gripper apparatus further comprises a linear motion producer coupled to the seating member and configured to provide controlled linear motion to drive the seating member along the gripper axis; and a seating member position controller electrically coupled to the linear motion producer and adapted to drive the seating member to any preprogrammed extension or retraction position alongside the first and second fingers.