A biological analysis system comprises at least two biological analysis devices connected to one another by a conveyor defining a closed circuit, each biological analysis device comprising at least one inlet and one outlet for racks of tubes, and at least one exchange region for exchanging racks of tubes with the conveyor, which exchange region is distinct from the inlet and from the outlet. The inlet of at least two biological analysis devices each form an inlet of the biological analysis system for racks of tubes, and the outlet of at least two biological analysis devices each form an outlet of the biological analysis system for racks of tubes. The biological analysis system further comprises a controller designed to command the transfer of a rack of tubes received in the biological analysis system via the conveyor to another biological analysis device according to the operations to be performed on the tubes in that rack and/or according to a respective workload status of the biological analysis devices.