Fast cell size distribution analysis by laser flow microphotometry-- applications to ciliate populations

The laser flow microphotometer for rapid cell size analysis is introduced. In contrast to known principles absorption is detected of a part of each cell only. Cell classification is achieved by pulse form analysis of absorption pulses. Cell lengths between 5 and 300 mum have been measured without changing the geometry of the flow system. Other ranges of size can be covered by changing the flow diameters. The principle can be applied to stained or unstained cells. No further preparation of samples is necessary. Examples of high speed measurements on different cell populations of unstained ciliated (Tetrahymena pyriformis), human blood and different pollen grains are given.