FCS Express allows you to easily create Gates, Quadrants and Markers to isolate specific populations and to retrieve statistics for them.

 

Gates are used to define regions of interest on 1D and 2D plots. FCS Express supports five types of drawing gates and another type, called combination gates, which can combine any number of other gates to create more complex gating strategies. Gates can be drawn with different shapes (e.g. Ellipse, Rectangle, Polygon, Freeform), exist in one or two dimensions (i.e. 1D vs 2D gate), and their content can be selectively displayed on new plots for further downstream analysis. FCS Express also includes Data Specific Gates, which are gates assigned to specific data files allowing for different gating positions between files for the same gate.

 

Markers are used to select regions of interest using a single parameter (i.e. one dimension). They can be drawn on either a 1D plot or a 2D plot (in the latter case, the marker will be drawn using the X parameter). In FCS Express, Markers drawn on 1D Plots are meant to retrieve statistics and cannot be immediately used for downstream analysis as gates (i.e. you cannot selectively display the content of a Marker drawn on a 1D Plot in a different plot until it has been converted to a gate). However, Markers can be converted to Gates with a few clicks. When Markers are converted to Gates, the events within them can be selectively analyzed for downstream analysis. Note that a marker drawn on a 2D Plot will automatically become a 1D gate and can be immediately used for downstream analysis.

 

Quadrants are used to divide the plot content in 4 complimentary, and mutually exclusive, regions. This means that the each event in the plot will be included in a quadrant and not in another. In FCS Express version 7.20 and later, Quadrants are converted to gates by default.