NOVELTY - A fuel cell cassette comprises assembled membrane electrode assembly, fuel flow field, and oxidant flow field to align their reactant and sealant manifold openings. A resin is introduced into peripheral edges of the membrane electrode assembly, fuel flow field, and oxidant flow field to encapsulate the periphery of the cassette. A sealant is introduced the sealant manifold openings.    USE - For electrochemical applications including fuel cell, as well as ion exchange applications.    ADVANTAGE - The invention allows the formation of an internal porting within the encapsulation, does not need for the separate step of port sealing individual components prior to the assembly of the fuel cell cassette, and develops fuel cell stacks and cassettes with enhanced reliability and reduction in labor and costs.    DETAILED DESCRIPTION - A fuel cassette comprises a membrane electrode assembly, a fuel (14, 15) flow field, and an oxidant (12, 13) flow field, each component having reactant manifold opening(s) and sealant manifold opening(s) extending through their thickness. The membrane electrode assembly, fuel flow field, and the oxidant flow field are assembled relative to each other so that the respective reactant manifold openings and at least a portion of sealant manifold openings are aligned. A resin is introduced in to the peripheral edges of the electrode assembly, fuel flow field, and oxidant flow field to encapsulate the periphery of the cassette, and a sealant is introduced in the sealant manifold openings to enclose those openings that are not intended to deliver material to a particular flow field.    INDEPENDENT CLAIMS are also included for:    (a) a fuel cell stack comprising the inventive fuel cell cassette(s), and end plate(s) having opening(s) which align the reactant manifold openings;    (b) a method of manufacturing the inventive cassette by sealing the periphery of the cassette and a portion of the cassette surrounding the sealant manifold by applying pressure differential to the cassette; and    (c) a method of manufacturing a stack comprising assembling the stack and applying a compression mechanism to seal the end plates and cassettes into the stack.    DESCRIPTION OF DRAWING(S) - The figure shows a manifold opening and injection hole pattern.    Oxidant (12, 13)    Fuel (14, 15)