- Flow cytometry is a laser-based biophysical technology employed in cell counting, cell sorting, and biomarker detection. Cells or materials are suspended in a stream of fluid and passed through the electronic detection apparatus. The equipment allows simultaneous multiparametric analysis of physical and chemical characteristics up to thousands of particles per second.
Figure 1. BD FACSCalinur Flow cytometer |
Figure 2. Figure depicting the laser, fluorescent channels, and cell sorting procedure. |
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Fluorescence-activated cell sorting (FACS) is a specialised type of flow cytometry. It provides methods for sorting a heterogeneous mixture of biological cells into two or more containers, one cell at a time, based upon the specific light scattering and fluorescent characteristics. These includes size, fluorescently labelled DNA sequence, and fluorescently labelled antibody on targeting antigen. It is a useful scientific instrument as it provides fast, objective and quantitative recording of fluorescent signals from individual cells as well as physical separation of cells of particular interest. Typical applications include sorting live and dead cells by Annexin V staining or segregating T cells through discrimination between CD4 and CD8 surface antigens.
Figure 3. Fluorescence-labelled antibodies binding to surface or intracellular biomarkers |
Figure 4. Radioactive-labelled antibodies binding to surface or intracellular biomarkers |
References:
- Ormerod, M.G. (ed.) (2000) Flow Cytometry — A practical approach. 3rd edition. Oxford University Press, Oxford, UK. ISBN 0-19-963824-1
- http://www.semrock.com/flow-cytometry.aspx
- http://www.the-scientist.com/?articles.view/articleNo/31438/title/Flow-Cytometry-for-the-Masses/
- http://www.bdbiosciences.com/research/ics/
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