The DURAN® stirred reactors are ideal for a wide range of mixing processes in laboratories, such as mixing liquids, dissolving solids, fermentations, hydrolysis, or cell culturing. The stirrers can be used with any standard commercial magnetic lab stirrer. Using an impeller suspended in the media provides a notably improved mixing compared to magnetic stir bars. The variable stirrer shaft can be used in 500, 1000, or 2000 mL DURAN® GLS 80® laboratory bottles. A separate, shorter shaft fits the 250 ml GLS 80® bottles. All the components are autoclavable and therefore suitable for biological applications such as in a low-cost bioreactor. Two types of interchangeable impellers are available: anchor or 8-bladed impeller (optional). These can be used up to 500 rpm. The 4 ports (2 x GL 14 and 2 x GL 18) provided permit the addition or removal of media from the bottle during the mixing process. By using additional components from the GL 45 and GLS 80® connection systems, tubing with outer diameters between 1.6 and 12.0 mm can be connected.