Particle classification and sorting systems and methods

An apparatus for processing particles in a particle flow, the apparatus comprising:

• means for delivering a microfluidic stream from a microfluidic aperture into a flow environment, the microfluidic stream comprising a particle flow comprising a plurality of particles;
• means for directing interrogating electromagnetic radiation at the particles in the microfluidic steam and monitoring responsive emissions from the irradiated particles;
• means for directing sorting electromagnetic radiation of at least some of the particles in the microfluidic stream in order to sort the particles into at least two populations dependent on the monitored responsive emissions of the particles;
• wherein the means for delivering the microfluidic stream is configured to maintain the microfluidic stream as a continuous phase flow of liquid when receiving said electromagnetic radiation.