The Clarisolve depth filter is a clarification device with a gradient density structure specifically designed to the particle size distributions of pretreated feed streams. It can eliminate the need for centrifugation, enabling the implementation of a single-use process train, while also reducing pre-use flushing requirements. It can also deliver improved volumetric capacity and reduced turbidity. The depth filters may be used in combination with a cationic pDADMAC (poly diallyldimenthyl ammonium chloride) flocculation reagent. Together, the Clarisolve and pDADMAC technologies can provide a solution for harvesting high cell density cultures that can be incorporated into current clarification platforms.