Disclosed herein are processes for collecting nucleic acids from particulate samples. One embodiment disclosed herein relates to the use of ultrasonic energy to simultaneously shear large nucleic acid molecules and large particulates to very small sizes prior to or during a chemical binding step to a nucleic acid binding surface. Another embodiment involves crushing the nucleic acid binding surface prior to eluting the bound nucleic acid molecules to enable better wetting of the nucleic acid binding surface and easier diffusion of bound nucleic acid molecules out of the nucleic acid binding surface.