Device and method for fragmenting material by hydrodynamic shear

A polymer-fragmentation kit designed for use with a centrifuge for fragmenting a sample solution of polymers, such as polynucleotides, into a plurality of polymer-fragment pools, each with a different fragment-size range, comprising

• a plurality of fragmentation devices, each device comprising
• (i) a substrate adapted to be supported within a centrifuge tube,
• (ii) formed in said substrate, a microchannel extending between upper and lower channel ends and defining a plurality of shear regions, where the shear regions in each device have a device-specific shear-region geometry designed to subject material present in the sample solution of polymers to a device-specific shearing force as sample solution is forced through the shear region under the influence of a selected centrifugal force applied to the tube in which the device is supported,
• wherein polymers contained in a liquid sample applied to the upper ends of different devices in the kit, with the devices supported in centrifuge tubes within a centrifuge, are fragmented by shearing as the samples are forced successively through the plurality of shear regions in each device, to produce polymer fragments having different size ranges.