Process and apparatus for cell sorting

An apparatus for separating physically distinguishable polymeric beads, comprising:

• means for suspending the polymeric beads in a suspension liquid and to form a suspension of the beads in the suspension fluid,
• means for channeling the suspension of beads into one or more flow tubes each having a bore less than two bead diameters and in which streams the beads are individually serially disposed, the flow streams being directed into the vicinity of the detection means,
• means for presenting the beads to a detection means which is adapted to non-invasively physically detect and distinguish individual beads into classes based upon physical characteristics of the beads or the adjacent vicinity of the beads;
• bead directing means adapted to physically separate beads of one of said classes from those of another class, and;
• control means adapted to control the bead directing means in response to the output of the said detection means so as to direct each bead to a defined destination.

An apparatus for separating physically distinguishable polymeric beads, comprising:

• means for suspending the polymeric beads in a suspension liquid and to form a suspension of the beads in the suspension fluid,
• a detection means which is adapted to non-invasively physically detect and distinguish individual beads into classes based upon physical characteristics of the beads or the suspension fluid in the adjacent vicinity of the beads,
• means for channeling the suspension of beads into one or more flow tubes in which streams the beads are individually serially disposed, the streams being directed to the detection means,
• means for presenting the beads to the detection means;
• downstream of the detecting and distinguishing means the flow tube terminating at an open end;
• a bead catcher having an entrance opening in a facing relationship to said open end, so that a bead may travel from the open end of the flow tube into the entrance opening of the bead catcher,
• flow control means provided at the open end of the flow tube and/or the entrance opening of the bead catcher to allow or prevent passage of a bead from the open end of the flow tube to the said entrance opening,
• a bead director tube in communication with the entrance opening of the particle catcher, the entrance opening of the bead catcher being at a higher atmospheric pressure relative to the bead director tube such that beads entering the entrance opening of the bead catcher are directed by the difference in relative air pressure along the bead director tube.