Hierarchical Gating#

Convert a hierarchical (binary) gating strategy into a categorical condition.

Hierarchical gating strategies are quite common when doing manual gating. For example, an 8-stain panel can separate monocytes into macrophages, B cells, NK cells, NKT cells, T cells, DCs, and neutrophils – but then, because these states are mutually exclusive, a reasonable question is “how much of each are there?” Cytoflow can define these gates, but because it does not have any concept of nested gates, plotting and analyzing this gating strategy can be challenging.

The Hierarchical Gating operation converts a list of gates into a categorical variable to enable straightforward analysis. For example, monocytes stained with CD64, CD3 and CD19 can differentiate between macrophages and B cells. A user defines a threshold gate to separate CD64+ cells (macrophages) from the rest of the events, then they use a polygon gate to distinguish the CD19+/CD3- cells (B cells) from everything else. The Hierarchical Gating operation can take these two gates and create a categorical condition with the values Macrophages, B_Cells, and Unknown.

The operation is set up by providing a list of conditions, values for those conditions, and the category that condition indicates. Figuring out an event’s category is done by evaluating the hierarchical gates in order. For each event, the first condition/value pair is considered. If that event has that value, its new category is set accordingly. If not, then the next gate in the list is considered. If the event is a member in none of the gates, it receives the category listed in the Default attribute.

Name

The name of the new condition that this operation creates.

Gates

The ordered list of gates that implement the gating hierarchy. For each, you need to specify:

  • The name of the pre-existing condition

  • The value that the condition has to have to indicate membership in this class.

  • The name of the new category.

Default

The name that unclassified events will have in the new categorical condition.