Abstract: Compounds which contain ammonium groups and sulphonic acid groups and which, in the betaine form, correspond to the formula ##STR1## wherein X denotes --CO-- or --SO.sub.2 --,R.sub.1 denotes hydrogen or alkyl,R.sub.2, R.sub.3 and R.sub.4, independently of one another denote alkyl, alkenyl or aralkyl, orR.sub.4 denotes ##STR2## Y denotes alkylene or xylylene, m denotes 1 or 2,n denotes 0 or 1, andR.sub.5 and R.sub.6, independently of one another, denote hydrogen, alkyl, alkoxy or halogen,and in addition, if n=1,R.sub.2 or R.sub.4 denotes amino, alkylamino, dialkylamino, aryl or cycloalkyl,R.sub.2 and R.sub.3, together with the nitrogen atom which is bonded to them, denote a 5-membered or 6-membered ring,R.sub.2, R.sub.3 and R.sub.4, together with the nitrogen atom which is bonded to them, denote a pyridinium ring, a group of the formula ##STR3## or hydrogen, Y denotes arylene, benzylene or a radical of the formula ##STR4## Z denotes a direct bond, --(CH.sub.2).sub.p --, --O--, --O--(CH.sub.2).sub.

Abstract: In fluorescence analysis of multiply stained particles, particularly biological cells, in a continuous flowthrough procedure, in which the particles are suspended in a carrier fluid, the carrier fluid containing the suspended particles is encased in a sheath stream, the resulting composite stream is conducted in laminar flow through an intensive laser light zone where fluorescent light pulses are generated by the action of the laser light on the particles and emanate from the particles, and those fluorescent pulses are detected and processed in real time in an electronic evaluation system, the laser light zone is produced by focussing at least two laser beams of respectively different wavelengths on two points spaced at a given distance apart along the path of the particle-containing fluid in the composite stream, and the detection and processing is effected by correlating the fluorescence pulses emanating from the two points on the basis of the spacing between the two points and of the flow speed of the stre