Fluorescence-activated cell sorter

Fluorescence-activated cell sorter, 26 971 Fluorescence band maxima, 20 512 Fluorescence detection, 17 635 Fluorescence detectors, liquid... 

A fluorescence-activated cell sorter (FACS) is a flow cytometry instrument used to separate and identify cells in a heterogeneous population. Cell mixtures to be sorted are first bound to fluorescent dyes such as fluorescein or phycoerythrin. The labeled cells are then pumped through the instrument and are excited by a laser beam. Cells that fluoresce are detected, and an electrostatic charge is applied. The charged cells are separated using voltage deflection. 

Electronic Standards for Transmission of Regulatory Information European Union antigen-binding fragment fluorescence-activated cell sorter fetal bovine serum constant fragment... 

Fluorescence-activated cell sorters (FACS) have been used to separate subpopulations of cells for subsequent treatment or analysis (see Chapter 30). However, this approach requires that the cells be in suspension. In the case of adherent cells, some cannot be easily suspended, or the treatments used to suspend them may interfere with subsequent analysis. In these situations, a laser microheam system capable of fluorescence imaging can serve two purposes. At low power, the laser can excite fluorescence to produce an image, and at a higher power, the laser can be used to kill the undesired cells. 

Sklar, L. A. and Finney, D. A. (1982) Analysis of ligand-receptor interactions with the fluorescence activated cell sorter. Cytometry 3,161-165. 

Measured after 5 hr of exposure to drug using a fluorescence activated cell sorter. Key -I- -i-, >75% of cells in mitosis -F 50-75% <50%. 

Newer strategies for stem cell identification have been developed based on the knowledge of cell functions. A primitive and multipotential subpopulation of bone marrow mononuclear cells has been identified on the basis of the intracellular presence of aldehyde dehydrogenase (ALDH). Those cells can be marked on the basis of the presence of ALDH and are called aldehyde dehydrogenase-bright cells (ALDH cells), allowing for their separation from a bone marrow aspiration mononuclear subpopulation under fluorescence-activated cell sorter (FACS) analysis. 

The various organs of the immune system such as spleen, lymph nodes, thymus and bone marrow containing the cells involved in the various immune responses offer the possibility to harvest these cells and perform in vitro assays for evaluation of effects on the immune system. When part of an in vivo animal study this may indicate a direct toxic effect of pharmaceuticals, that is, immunosuppression (Table 18.2). So, it is feasible to obtain cell suspensions for further evaluation such as determination of cellular subsets of T and B leukocytes by fluorescent activated cell sorter analysis (FACS analysis), and determination of natural killer (NK) cell activity of the spleen cell population. An advantage of this approach is that it may lead to identification of a biomarker to be used in clinical studies. In addition, in vitro stimulation of spleen cells with mitogens activating specific subsets may indicate potential effects on the functionality of splenic cell populations. Concanavalin A (Con A) and phytohemagglutinin (PHA) activate Tcells, while lipopolysaccharide (LPS) activates primarily B cell populations. Blood is collected for total white blood cell (WBC) determination and blood cell differential count. In addition, serum can be obtained for determination of serum immunoglobulins. 

Fluorescence-activated cell sorter (FACS) To predict and select cells in the population that express target protein Sensitive and allows direct sorting and cloning of positive cells Required proteins expressed intracellnlarly or on the cell snrface. Not sensitive for expression system engineered to secrete the protein... 

Parks, D. R., Bryan, V M., Oi, V. I, and Herzenberg, L. A (1979) Antigen-specific identification and cloning of hybridomas with a fluorescent-activated cell sorter (FACS) Proc Natl Acad Sci USA 76, 1962-1966... 

Fluorescence-activated cell sorter (FACS), e.g., Becton Dickinson FACScan (see Chapters 33 and 34). 

A third aspect of flow cytometry (known sometimes simply with the acronym for fluorescence-activated cell sorter, FACS, or even more familiarly as just flow) that distinguishes it from many other techniques is the way in which its wide and increasing usefulness has continued to surprise even those who consider themselves experts. What began as a clever technique for looking at a very limited range of problems is now being used in universities, in hospitals, within industry, at marine stations, on submersible buoys, and on board ships plans have existed for use on board space ships as well. The applications of flow cytometry have proliferated (and continue to proliferate) rapidly both in the direction of theoretical science, with... 

Wolff, A., Perch-Nielsen, I.R., Larsen, U.D., Friis, P., Goranovic, G., Poulsen, C.R., Kutter, J.P., Telleman, P., Integrating advanced functionality in a microfabricated high-throughput fluorescent-activated cell sorter Labchip 2003, 3, 22-27. 

Individual cells can be identified using a flow cytometer. Antibodies, coupled to fluorescent compounds, that bind to molecules on the surface of particular types of cells can be used to separate cells from each other in a fluorescent-activated cell sorter. 

Asp aspartic acid FACS fluorescence-activated cell sorter... 

DOTMA E. coli E EBV ECFP ECV EGFP ELISA EYFP FACS FdG FH2 FH4 FK506 FLP propane-aminium-trifluoracetate 7V-[2,3-(dioleyloxy) propyl]-/V,/V,/V-trimethyl ammonium chloride Escherichia coli erythromycine operon/repressor Epstein-Barr virus enhanced cyan fluorescence protein extracellular viral particles enhanced green fluorescence protein enzyme-linked immunosorbent assay enhanced yellow fluorescence protein fluorescence-activated cell sorter fluorescein di- 3-D-galactopyranoside dihydrofolate tetrahydrofolate human immunophilins native recombinase isolated from the 2pm plasmid from Saccharomyces cerevisiae... 

Herzenberg, L.A., Parks, D., Sahaf, B., Perez, O., Roederer, M., and Herzenberg, L.A. 2002. The history and future of the fluorescence activated cell sorter and flow cytometry A view from Stanford. Clin Chem 48 1819-1827. 

Analysis is best carried out by a fluorescence activated cell sorter (see 10.7.5) but, if the cells are pulse labelled with [3H]-thymidine immediately before harvesting the proportion of cells in S-phase in the various fractions can be estimated by autoradiography (see 12.3). The problem with this procedure is that the machines can become contaminated with radioactivity and the tritium may interfere with subsequent enzyme assays. Labelling of a sample after fractionation is a poor alternative, but prior pulse labelling with bromodeoxyuridine allows S-phase cells to be detected using a fluorescent antibody 12.7.5. 

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