The Group panel is the top portion of the Analysis tree. It is used to organize samples into sets for common analysis and reporting.
Almost all cytometry experiments involve collecting multiple samples that fill distinct roles within the experimental design. Some files may serve as compensation controls or experimental controls, others as fully stained experimental files, and others yet as a follow up validation experiment. Groups can be used in FlowJo to partition the data so that you may act on multiple files, expediting your analysis.
Groups are the basic functional unit in FlowJo.
Overview
Groups work as filters. Selecting a group causes only populations and samples associated with the selected group to be displayed in the Sample and Population panels, respectively. Observe in Figure 1(a) that the experiment group is selected, and the Populations panel shows only the ungated cells, while the Samples panel shows a scrollable list that includes the 15 samples in the Experiment data group. In Figure 1(b) the PMA group has been selected so now populations present on the samples in the PMA group are visible in the Populations Panel, and only the 6 samples in the PMA group are visible in the Samples Panel at the bottom of the Analysis Hierarchy.