Fluorescence-activated+cell+sorter


 * Fluorescence-activated cell sorter**, a type of flow cytometry, is a way of sorting labeled cells from non-labeled cells. These cells are first drawn from intact tissue then coupled with a specific antibody to bind to a specific type of cell in the tissue. The cell concentration of the solution is then adjusted so that when put in the fluorescence-activated cell sorter, the droplets contain at most one cell each. Each machine can sort many thousands of cells per second and can pick-out 1 cell from a pool of 1000 cells and accurately label it.



Purpose: The purpose of this technique is to take a heterogeneous mixture and create two homogeneous mixtures. Scientist use this technique because it is a fast and accurate way to separate cells of interest. FACS is used for many reasons in research because it can sort small sample sizes, the information can then be used to measure internal proteins, and many other reasons. This also allows for detailed phenotyping of many samples such as, TILs, residual tumor cells, neonatal blood, rare event anaylsis, and fetal cells from the mother blood. FACS is also said to measure gene expression in single cells in large amounts with a large dynamic range of being able to pick cells from many molecules.

History: Mack Fulwyler invented the first cell sorting machine in 1965 called the Coulter principle. Len Herzenberg branched off of Fulwyler’s idea and made the fluorescence-activated cell sorter. For this production he won the Kyoto Prize in 2006. FACS uses a drop separation that was first invented by Richard Sweet as part of the ink-jet printer.

Current Research: Fluorescence-activated cell sorting allowed researchers here to remove certain embryonic stem cells from the mix of all of the other types of cells. They needed the undifferentiated hESC cells removed in order to test the risks of tumorigenesis. Using this technique, they concluded that it eliminated what they needed based on the cell-surface antigens that are expressed.

This review talks about the different uses for FACS and specifies on the advantages of using FACS. It raves about FACS being able to “provide quantitative data for each and every variant in the library.” The paper goes into detail about the how this technology will be able to be used for protein engineering and directed enzyme evolution. Due to this technology being expensive, there has not been a lot of research labs using this.

This paper used FACS to couple with cDNA microarrays to simplify the mixing of many signals and different cell types while researching brain tissue. This technology allowed the researchers to use the genes with the highest expression, which was sorted using FACS and actually was proven to successfully isolate specific cells needed for the experiment.