A method of constructing a point-of-care diagnostic apparatus and fluid storage and delivery apparatus therefor is provided. The method of constructing the fluid storage and delivery apparatus includes providing a flexible upper layer having a reservoir; providing a flexible lower layer having a valve member; providing a rigid substrate having an upper surface, a lower surface and a through port; disposing a fluid in the reservoir; and sandwiching the rigid substrate between the upper and lower layers and bonding the upper layer to the upper surface of the rigid substrate with the reservoir registered with the through port and bonding the lower layer to the lower surface of the rigid substrate with the valve member registered with the through port. The method of constructing the point-of-care diagnostic apparatus includes fixing the fluid storage and delivery apparatus to a rigid base in selective fluid communication with a reaction chamber.