Abstract: An apparatus for sorting particles comprises a nozzle or the like for producing a stream of particles, such as cells, in a liquid flow. The particles are analyzed as they are flowing to detect different parameters thereof. A hollow inner tube and a concentrically arranged hollow outer tube are located downstream of the analyzing area. Gas bubbles are generated in the inner tube to prevent particles from flowing therein and to deflect particles into the annular space between the inner and outer tubes. Gas bubble generation is coordinated with the particle analysis to selectively deflect particles having the different parameters into the annular space, whereby the deflected particles are sorted for collection. A method of sorting particles, such as cells, substantially in accordance with the above-described apparatus is another aspect of the present invention.

Abstract: A device, particularly suitable as a connector, comprised of a housing having an open end closed by an elastomeric membrane. The membrane has at least one preformed opening, which is normally closed and which is opened upon deformation of the membrane, with the opening being reclosed upon release of the deformation force. The housing interior may include means for applying a deformation force to the membrane to open the opening therein.

Abstract: A method and apparatus are provided for determining the count per unit volume, that is, the density of particles such as platelets in diluted whole blood. The invention involves use of known information, namely, the count per unit volume of other (reference) particles, such as red blood cells, also suspended in the same sample of liquid. The other particles are generally distinguishable from the particles of unknown count per unit volume by a difference in some measurable characteristic of the particles, such as size.