Computer-assisted centrifugal elutriation. I. Detection system and data acquisition equipment.

To optimize cell separations by centrifugal elutriation, we constructed an on-line computer-controlled multiparametric light-scatter system. A bypass sample flow, at the outlet of an elutriation rotor, is hydrofocussed and three scatter parameters of each cell are determined up to a maximum of 15,000 cells/second. The 18-bit representation of the parameter values are cumulatively stored by means of a direct memory access interface. The histogram memory is continuously displayed to provide information on the number and type of cells that are elutriated. A special purpose operating system, implemented on a stand-alone computer configuration, allows a high data-acquisition rate and ample data processing capacity. In addition, a local network driver was constructed to facilitate off-line detailed analysis of the data. The equipment is well suited to monitor the centrigural elutriation process. The flexibility of the system allows an extension of the monitor to computer-controlled elutriation.