Disclosed are methods, compositions and kits for contacting a sample containing a biological particle with a catalyst associated with or attached to a support. The biological particle may be cells and/or nuclei. The catalyst may be an enzyme configured to digest an extracellular molecule, such as an extracellular biological molecule, including extracellular nucleic acid molecules. In some examples, the biological particle is an aggregate of cells that is processed to single cells with a nuclease that is attached to a bead support. The bead and nuclease may subsequently be removed from the system. The single cells that result from the method can be used in single cell-based droplet systems for obtaining genome or transcriptome profiles of single cells.