Filter and test device containing same, with flow-delaying polymer.

摘要

There is disclosed a filter and a device (10) positioning the filter membrane (16) between an upper (12) and a lower (14) chamber or compartment, particularly useful in an immunoassay. The filter and device are improved in that the filter membrane is overcoated with at least one water-soluble polymer of a type, a molecular weight, and at a dry-solids coverage effective to create for that membrane an induction time at room temperature of at least about 30 seconds and no greater than about 300 seconds, for a liquid head of pressure of about 6 mm of water.