Laser-Based Multiparameter System for Automatic Sorting of Microscopic Particles

The design, characteristics and experimental results of a Laser-Based Multiparameter system for automatically sorting microscopic particles are described. The system is used mostly for the analysis of biological cells which have been stained with fluorescent dyes and suspended in liquids. The cells, passing in single file through an elliptically focused laser beam, emit fluorescent signals, which are detected by sensors and processed, first in analog fashion and then digitally by a multichannel pulse-height analyzer. The two-color fluorescent and light scatter signals give certain parameters of the particles being measured. Sorting rates of several hundred per second are attainable. The high resolution and good stability of the system ensure fast, reliable and statistically meaningful measurement of particle populations.