Patent ID: 7105355

Claim:
A flow cytometer cell, comprising a) fluid sample inlet comprising a fluid sample channel; b) at least one focusing fluid inlet comprising a fluid focusing channel; c) a convergent focusing zone, said fluid sample channel and said fluid focusing channel communicating with an upstream end of said convergent focusing zone, said convergent focusing zone narrowing to form an inlet to an interrogation zone; d) an interrogation zone, said interrogation zone comprising a channel through which sample fluid enveloped by focusing fluid flows, said interrogation zone terminating in an outlet, further comprising at least three optical waveguide light impingement and/or collection path(s), internal ends of said optical waveguide light path(s) terminating at or proximate to said interrogation zone, an opposing end of said optical waveguide light path(s) in communication with or adapted to be placed in communication with a light source or a photodetector, said at least three fiber optic waveguides comprising at least a first fiber optic wave guide illuminating said interrogation channel, and at least two fiber optic waveguides conveying light from said interrogation channel to at least one detector, said three fiber optic waveguides all located in a plane which includes the interrogation channel.