TRA will manufacture and test three cell harvesting devices using technology developed during NIH Phase I SBIR research. The first device is a platelet harvester that uses TRA's unique and now patented ultrasound technology to collect and concentrate platelets that have not been damaged by compaction and activation. TRA proposes to also use this new acoustic force technology to replace centrifugal force in separation technique known as Seteric Sedimentation Field Flow Fractionation. SSFFF is used to separate classes of cells (or other 1 to 100 micron particles) in flow tubes on primarily the basis of size. Ultrasonic transpost of these cells will allow the elimination of a continuous flow centrifuge as part of the apparatus. Finally, TRA will develop a new type of cell sorter based on an ultrasonic velocity separation techniques demonstrated in the Phase I research which will separate selected particle sizes from solutions containing a wide range of particle sizes. Prototype of this separation device will be constructed for demonstration to Phase III commercial interests.