Flow cytometric analysis by using micro-machined flow chamber

Effect of the flow characteristics in a newly developed micro-machined sheath flow chamber on the accuracy of cytometric analysis was investigated. The chamber was formed by laminating three 100-mu m-thick photo-etched metal plates. Sample fluid containing cells, which enters the chamber via an axial specimen nozzle, is enveloped by a buffering sheath-fluid and transported to a capillary channel. Microscopic observation and three-dimensional viscous flow analysis predict that the dispersion of cells in the capillary channel is favorably reduced when the Reynolds number is between 500 and 750, which is value associated with low deviation of the analytical results. The five classifications of human white blood cells were determined, and this verified that change of the deviation depends on the Reynolds number. The results confirm Reynolds number of 500 - 750 is appropriate for good classification.