A combined diagnostic device/housing combination is described. In its preferred application it is adapted to the detection of biological particles by the utilization of the phenomenon by which such biological particles interact specifically either immunologically or non-immunologically. The combination comprises a tube closed at one end, means (i.e., a cap) removably engageable with the opposite end of the tube to achieve sealing thereof such as to preclude the entry of microorganisms, a rod-like member affixed at one end thereof to the sealing means so as to project therefrom and a functional test device affixed to the free end of the rod-like member. When assembled, the rod-like member and test device are disposed within the tube and the tube is sealed ready for storage, shipping and/or use. Preferably, when the test device is for testing for specific biological particle interaction, the complete structure is made of glass and/or metal.