The present invention relates to the formation of a gasket, sealing area or O-ring, such as a gasket on a screen for a filtration module such as a TFF or NF cassette or an O-ring on the outlet of a filter cartridge wherein the seal is proud of at least one surface of the screen. Preferably, the seal is molded to the filter component, more preferably it is injection molded to the component. The seal maybe formed of any elastomeric material such as thermoplastic, thermoplastic elastomers, thermosets and rubber, both natural and synthetic. The molded seal provides better sealing, allows for a variation in heights and geometries, and provides better cleanliness and lower extractables than the currently used adhesives or conventional gaskets or O-rings.