A method of screening protein crystal growth conditions on a nano or meso scale comprises providing a micro-electromechanical chip with a plurality of micro-chambers in the micro-electromechanical chip. A protein solution is placed into the micro-chambers by an automated jet type dispensing means with nano or meso scale precision. The protein crystal growth conditions of each of the micro-chambers is adjusted so that the protein crystal growth conditions of each of the micro-chambers differs. Crystallization of the protein solution in the micro-chambers is effected. Protein crystal growth in the micro-chambers is then observed.