Flow cytometry        

By  measuring  the  light  they  scatter,  or  the fluorescence they emit, Different  cells  can  be  identified  as they pass a laser beam in a flow cytometer. activated cell sorter or FACS an instrument based on flow cytometry, in a fluorescence  cells  can be recognizes  and separated  from  each  other.  The cells  of

A fluorescence-activated cell sorter. An antibody specific for a particular cell surface protein is associated to a fluorescent molecule and then added to a mixture of cells. For fluorescence When the specific cells pass through a laser beam they are monitored. Droplets containing single cells are given a positive or negative charge, based on whether the cell has limited the fluorescently-tagged antibody or not. Droplets containing a single cell are then de?ected by an electric field into collection tubes according to their charge.

Interest are first labeled with an antibody  which is individual for a particular  cell surface  molecule.  Antibody is coupled to a fluorescent dye, like when in a narrow stream the individual cells pass a laser beam in single file, the fluorescence  of each cell is measured. A vibrating nozzle then forms small droplets which each containing a single cell which are given a negative or positive charge based on whether the cell they contain is fluorescing.  A strong electric field defects the various  charged droplets into separate containers  so that each container  has a homogeneous  population  of cells eventually  with respect to the cell surface  molecule  tagged  along  fluorescent  antibody. For  biochemical   analysis  or  grown  in culture These  homogeneous  populations   may  then  be  used. By  flow cytometry The  RNA and DNA  content  of  a cell  can  be  measured also.