An apparatus comprising: a frame; - a sample tray holding area including a first, and a second tray holder (300A, 300B) disposed in a tray holder plane, each tray holder (300A, 300B) being configured for a sliding insertion of one or more sample trays into the tray holder (300A, 300B) and for holding the sample tray so that longitudinal axes (SCLA) of sample holders within the trays extend outward of the tray holder plane; a drive section connected to the frame; and characterized in that: - the first and the second tray holders (300A, 300B) are separated from each other by an aisle between the first and the second tray holder (300A. 300B); and the apparatus further comprising: a transfer arm connected to the drive section and being disposed in the aisle between and separating the first and the second tray holder (300A, 300B), the transfer arm including a rotation axis oriented substantially parallel with the longitudinal axes (SCLA) of sample holders, a sample gripper (440A, 440A', 440A", 440A′′′), and a push member (420, 430) configured for linear movement relative to the sample gripper (440A, 440A', 440A", 440A′′′), where the sample gripper (440A, 440A', 440A", 440A′′′) and push member (420, 430) are arranged so that the sample gripper (440A, 440A', 440A", 440A′′′) and push member (420, 430) rotate about the rotation axis. a frame; - a sample tray holding area including a first, and a second tray holder (300A, 300B) disposed in a tray holder plane, each tray holder (300A, 300B) being configured for a sliding insertion of one or more sample trays into the tray holder (300A, 300B) and for holding the sample tray so that longitudinal axes (SCLA) of sample holders within the trays extend outward of the tray holder plane; - a sample tray holding area including a first, and a second tray holder (300A, 300B) disposed in a tray holder plane, each tray holder (300A, 300B) being configured for a sliding insertion of one or more sample trays into the tray holder (300A, 300B) and for holding the sample tray so that longitudinal axes (SCLA) of sample holders within the trays extend outward of the tray holder plane; a drive section connected to the frame; and characterized in that: - the first and the second tray holders (300A, 300B) are separated from each other by an aisle between the first and the second tray holder (300A. 300B); - the first and the second tray holders (300A, 300B) are separated from each other by an aisle between the first and the second tray holder (300A. 300B); and the apparatus further comprising: a transfer arm connected to the drive section and being disposed in the aisle between and separating the first and the second tray holder (300A, 300B), the transfer arm including a rotation axis oriented substantially parallel with the longitudinal axes (SCLA) of sample holders, a sample gripper (440A, 440A', 440A", 440A′′′), and a push member (420, 430) configured for linear movement relative to the sample gripper (440A, 440A', 440A", 440A′′′), where the sample gripper (440A, 440A', 440A", 440A′′′) and push member (420, 430) are arranged so that the sample gripper (440A, 440A', 440A", 440A′′′) and push member (420, 430) rotate about the rotation axis.