Dual chamber microplate washer

A novel apparatus is disclosed for the alternate filling and evacuation of all wells simultaneously of a multi-well microplate. The apparatus consists of a flat, horizontally disposed distribution head comprised of an upper and a lower chamber formed by these parallel plates, with a rectangular array of tubes passing through the lower of the three plates such that two tubes are aligned with each well of a microplate, one for filling and the other for evacuation. The filling tubes and evacuation tubes extend below the lower plate for unequal distances, the evacuation tubes being the more extended. All filling tubes communicate with one of the two chambers in the distribution head, while all evacuation tubes communicate with the other. The microplate is supported below the distribution head with the tubes in proper alignment, and means are provided for bringing the microplate and the tubes in close proximity, for applying a vacuum to the chamber communicating with the evacuation tubes, and for supplying pressurized wash fluid to the chamber communicating with the filling tubes. The apparatus provides a faster washing process for microplates, and is more reliable and efficient than devices already known for the same or similar purposes.