Patent ID: 7459128

Claim:
A device for storing and dispensing a mixture of a first liquid and a second liquid into an array of wells in a multi-well container, the device comprising an array of isolated, sealed, tapped reservoir units, each unit containing an integrated metering tap including a dispensing tube having an outer surface and defining an inner cavity open at a lower end of the tube, the tube also defining a metering capillary extending through a side wall of the tube between the inner cavity and the outer surface, the metering capillary sized to draw in a known volume of the first liquid; and a tap drive channel in communication with the inner cavity, the tap drive channel pressurizable to pump the second liquid along the inner cavity of the tube so that a lower meniscus edge of the second liquid is below the metering capillary; draw the first liquid from the metering capillary into the second liquid via diffusion or forced vacuum; mix the first liquid and second liquid in the tube by hydraulically moving the second liquid up and down inside the tube, to form a mixture; and then to expel the mixture from the tube by pumping the mixture to the end of the tube.