High-speed cell sorting is currently being used in a number of clinical applications due to its obvious benefits of speed and purity. These applications include rare-cell sorting for the enrichment of stem cells, DCs, fetal cells in maternal circulation, Ag-specific T cells, as well as tumor-cell detection and enrichment for residual disease diagnosis, or depletion for transplant purging. Highspeed sorting is not limited to rare populations, as sperm sorting for gender selection demonstrates. Operators performing clinical flow sorting may come into contact with potentially infectious material. Since cell sorters can generate aerosols, aerosol-containment systems should be used for instrument-operator protection. In addition, if flow sorting is to be used to purify cell populations for reinfusion into patients, a more rigorous set of precautions is needed to protect the sample during this process. Cell sorter manufacturers have devised equipment to help with these goals, and the solutions currently available for the Cytomation (Fort Collins, Colorado) MoFlo high-speed cell sorter were presented. Overview of high-speed sorting technology There are requirements of both the instrumentation and cellular sample for high-speed cell sorting. Instrumentation should be designed at the outset with this capacity in mind. Cellular samples must be at a high concentration in order for the machine to properly utilize such a system, allowing a high-speed train of single cells to be presented. Instrumentation can also be used for conventional sorting (, 10 000 event/s), with cell samples at lower concentrations giving excellent results.