APPARATUS FOR DISPENSING A PREDETERMINED VOLUME OF A LIQUID

摘要

Apparatus for dispensing a predetermined volume of a liquid (18) comprises a reservoir (12) for the liquid, a channel (13) provided with an outlet (16) for conveying the liquid (18) from the reservoir to the outlet, and means for generating a pulse of gas. The apparatus is arranged such that the flow of gas causes a predetermined volume of liquid to be ejected from the outlet. The outlet comprises a pair of openings in the channel which face one another, the liquid being retained between the openings by surface tension in the absence of a flow of gas. The gas flow is directed towards one of said openings in use. The apparatus may be used to dispense volumes of a liquid reagent in the range 1 nl to 2 mu l. The apparatus avoids contamination of the liquid, and dispensing head construction allows devices to be low cost disposable units. The apparatus is less sensitive to liquid viscosity than existing devices.