Tube holder for 0.2 ml tubes - Bioruptor® Pico. The tube holder for 0.2 ml tubes has been especially designed for being used with the Bioruptor® Pico and to guarantee homogeneity of chromatin and DNA shearing. It allows for reproducible sonication of up to 16 x 0.2 ml tubes at a time with a sample volume range of 20 to 100 µl. The holder is made up of a tube holder and its specific dock that makes the sample preparation more ergonomic.