A filter assembly includes a housing having an inlet port, an outlet port, and an interior compartment, the inlet port and the outlet port fluidically coupled to form a flow path in the interior compartment, a filter membrane in the flow path, the filter membrane having a porosity capable of capturing biological molecules as liquid flows along the flow path, a fluid screen in the flow path on an opposite side of the filter membrane from the inlet port, and a desiccating element in the flow path comprised of one of a hygroscopic or hydrophilic material selected to absorb moisture from the filter membrane at ambient temperature.