Abstract: A membrane actuated fluid dispensing head apparatus and method for dispensing fluids. The dispenser housing has a top plate, a bottom plate, and a fluid distribution plate disposed between the top and bottom plates. The top plate has fluid inlet means therethrough for admitting pressurized fluid over the distribution plate, the bottom plate having a plurality of elongated hollow pipettes thereon extending away from the top plate and in fluid communication with the fluid distribution plate. A first resilient membrane is disposed between the fluid distribution plate and the bottom plate, the bottom plate having a plurality of spaced cavities thereon having outer peripheries and in fluid communication with the pipettes. A second resilient membrane is disposed between the top plate and the distribution plate having an opening therethrough.

Abstract: A microdroplet test apparatus for use in HLA typing. The apparatus is an improvement upon the well known Terasaki tray which is in use for determining HLA antigens by measuring lymphocyte cytotoxicity. The apparatus includes a tray having a plurality of microtest wells wherein the sides of the microtest wells are designed to promote localization of lymphocytes or other cells being tested at the microtest well bottom. The apparatus further includes a cover having either rods or tubes which extend down into the test solution present in the microtest well to thereby control the amount of test solution which is present in the cylindrical optical view path through which the test solution is viewed by microscope for test result measurements.