Tube holder for 1.5 ml tubes - Bioruptor® Pico. The tube holder for 1.5 ml tubes has been especially designed for being used with the Bioruptor® Pico and to guarantee homogeneity of chromatin or DNA shearing. It allows for reproducible sonication of up to 6 x 1.5 ml tubes at a time with a sample volume range of 100 to 300 µl. The holder is made up of a tube holder and its specific dock that makes the sample preparation more ergonomic.