Flow cytometry is a laser- or impedance-based, biophysical technology employed in cell counting, cell sorting, biomarker detection and protein engineering, by suspending cells in a stream of fluid and passing them by an electronic detection apparatus. It allows simultaneous multiparametric analysis of the physical and chemical characteristics of up to thousands of particles per second.
Flow cytometry is mainly used in medical research (blood and tissue), and especially in detecting blood cancers. There are also applications in the food industry and in oceanography.
PCS uses the flow cytometry technique in the field of plant breeding and plant biotechnology. The technique PCS uses is based on the measurement of the intensity of the fluorescence of nuclei, stained with a DNA specific dye.
The quantity of the fluorescence is an indication of the amount of DNA in a cell nucleus. We compare the intensity of the fluorescence of the cell nuclei of an unknown plant with that of a control plant of which the number of chromosomes is known. By doing this, an accurate indication of the number of chromosomes of the unknown plant can be determined.
Plant chromosomes are often too small or too numerous for accurate counting by microscope. Furthermore, microscopic counting is laborious and very time consuming. And often there are just a few cells in a microscopic slide good enough for visual counting.
With flow cytometry we measure in a few minutes the DNA amount of thousands of nuclei. Therefore this technique is an outstanding alternative for microscopic counting of chromosomes.