an integrated titer plate - injector head for preparing and storing two - dimensional arrays of microdrops and for ejecting part or all of the microdrops and inserting same precisely into 2 - d arrays of deposition sites with micrometer precision . the titer plate - injector head includes integrated precision formed nozzles with appropriate hydrophobic surface features and evaporative constraints . a reusable pressure head with a pressure equalizing feature is added to the titer plate to perform simultaneous precision sample ejection . the titer plate - injector head may be utilized in various applications including capillary electrophoresis , chemical flow injection analysis , microsample array preparation , etc .