Polypropylene rack autoclavable to 121°C, arranged on 4 levels: • Lower level: 12 holes for 0.2 ml microtubes • Second level: 14 holes for 0.5 ml microtubes • Third level: 12 holes for 1.5 and 2 ml microtubes • Top level : Last line of holes (top level) is also a workstation for microtubes so they can be opened and closed just using one hand. Thanks to the locking system the tubes securely locks and not turn.