Abstract: This invention provides a pressure assisted valve for filling toilet cisterns. The valve has a chamber with an inlet and an annular outlet around the inlet. A diaphragm closure member is located over the inlet and outlet with its upper surface exposed to the chamber. Located through the diaphragm is an axially movable pintle and a chamber vent opening from the chamber is closable by an enlarged upper end of the pintle. The pintle is has longitudinal ribs on its outer surface to provide a bleed passage past the diaphragm. The lower end of the pintle is supported in a perforated guide in the inlet which is resiliently biased to close the enlarged end of the pintle against the chamber vent opening. A control spindle extends through the chamber vent opening from the enlarged end of the pintle. A manipulating mechanism acts on the spindle to move the pintle to open the chamber vent opening. The valve makes use of differential surfaces on the diaphragm to control the flow of water from the inlet to the outlet.

Abstract: A multiwell plate for microarraying comprising a self-sealing lower membrane and optionally also a self-sealing upper membrane. Spotting is performed by pushing a pin down through the liquid and then on to pierce the self-sealing lower membrane. A slide having an upper spotting surface is arranged under the well plate. The liquid sample forced through the lower membrane by the pin tip can thus be deposited directly onto the spotting surface. The pin is then withdrawn upwards through the lower membrane, which automatically reseals preventing further loss of liquid. The optional resealable upper membrane also prevents loss of sample liquid by evaporation and spillage. By contrast to the prior art, there is the major advantage that the pin head does not have to traverse between the well plate and slide to collect sample liquid, thus dramatically increasing operational speed for an automated microarraying apparatus employing the multiwell plate. Excellent spot reproducibility is also observed.