the test kit includes a substrate and , welded or bonded thereto , a plastic sheet having blisters . one of the blisters is shaped as a siphon . the other blisters act as reaction vessels and also serve to receive and store a reagent . the test kit may contain a test strip in one of the blisters . the test kit is particularly suited for carrying out immunological tests , whereby the siphon markedly facilitates the procedure during the washing step .