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Biomedical subjects

R T Stovel

Publications and source records attributed to R T Stovel.

3 recordsLinked to original sources

Individual cell sorting.

Current cell sorting machines do not preserve the individual identity of processed cells; after analysis, the cells are assigned to a subpopulation where they are pooled with other similar cells. This paper reports progress on a system that sorts cells individually to precise locations on a microscope slide and preserves them for further observation with a light microscope while recording flow measurement data for each cell. Various electronic and mechanical modifications to an existing sorting machine are described that increase drop placement accuracy and permit individual cell sorting.

Animals

A means for orienting flat cells in flow systems.

Flattened cells, such as red blood cells, epithelial cells, and sperm of many species, cause problems for fluorescence-activated cell analysis and sorting machines because the flow systems of such devices are unable to control the orientation of these cells as they flow past the detectors. For this reason, the fluorescence or scattered light measurements for identical cells may vary greatly. A flow geometry is here described that orients flat cells in a coaxial flow system so that each cell presents the same aspect to the observation device. A wedge-shaped exit on the sample injection tube in a coaxial flow system is sufficient to produce the desired orientation effect when used with low sample flow rates. Data is presented showing the effect of orientation of fixed chicken erythrocytes on histograms of small forward-angle light-scattering measurements.

Cytological Techniques

The influence of particles on jet breakoff.

Experimental observations of the breakup of a liquid jet issuing from a vibrated nozzle support the view that particles passing through the orifice tend to create a surface disturbance which, depending on the phase relative to the nozzle vibration, may either add to or subtract from the disturbance created by the nozzle vibration. The result may be either a shortening or lengthening of the jet breakoff length, depending on phase. The implications for sorting large cells with a fluorescence-activated cell sorter are discussed.

Cell Line