The world’s first portable acoustic cytome-ter (PAC) harnesses acoustic waves to focus cells into a tight, centered stream for analy-sis. The result is greater throughput and sen-sitivity than conventional flow cytometers without the need for large volumes of puri-fied water and for thousands of dollars less. Developed by researchers with the National Flow Cytometry Resource (NFCR) at Los Al-amos National Laboratory (LANL), the PAC is one of six R&D 100 Awards won by the flow cytometry team at LANL.Conventional flow cytometers measure the physical and biochemical characteristics of cells, or any particle, and are standard di-agnostic equipment in clinical laboratories and medical centers, where they produce blood cell and leukocyte subpopulation counts, and monitor levels of lymphocytes. A “sheath” fluid, usually a buffered saline solu-tion, hydrodynamically focuses cells through a laser beam, requiring both additional fluidic control systems and the use of large quan-tities of purified water. Conventional equip-ment requires expensive light sources and detectors to adequately illuminate samples and ensure that enough scattered and emit-ted light is collected for analysis. The com-plexity of the fluidics system and the need for high-quality lasers and detectors make most commercial flow cytometers bulky, ex-pensive, and fragile. The PAC uses a single ultrasonically vibrated capillary in place of the complex fluidics sys-tem. Eliminating the sheath reduces instru-ment size and complexity, operating costs, use of consumables, and waste. This is par-ticularly important in the field or in less-de-veloped areas of the world, where clean wa-ter can be a scarce and valuable commodity. The PAC will make it possible for doctors or technicians to make diagnoses using a smaller, simpler, more rugged instrument that uses fewer consumables and generates minimal waste. In an effort to bring new particle analysis ca-pabilities such as the PAC to clinicians and researchers worldwide, Acoustic Cytome-try Systems (ACS), LLC, a company spun off from LANL, was founded in 2006 in Los Alamos to commercialize acoustic focusing technology in flow cytometry and sample preparation.