Virtually Concatenated Populations (VCP) is a mode in FlowJoTM 11 showing an entire group of samples concatenated together without having to create a new file.
VCP is mode is toggled on/off simply by clicking the test tube icon in either the sample list or in the primary graph. You'll notice that while in VCP mode the icon has three test tubes, and in single sample mode it has one test tube. The toggle buttons are connected and change together if one is clicked.
The example below shows a comparison of VCP mode off/inactive (Figure 1a, only one test tube icon) and on/active (Figure 1b, three test tubes icon). Observe that there are far fewer cells visible when VCP is inactive, as only a single sample is graphed. When VCP is active, all of the samples in the Full Stained group are displayed.
In the same way, the statistics in the hierarchy reflect this selection displaying 336,843 Live cells when VCP is inactive (Figure 1a), and displaying 1,140,891 Live cells when VCP is active (Figure 1b).
(a)
(b)
Figure 1. (a) Virtually Concatenated Population Mode off. (b) Virtually Concatenated Population Mode on
VCP mode can be very useful for performing clustering or dimensionality reduction on an entire experiment, and then later viewing the results on individual samples. It can also be useful for drawing manual gates while visualizing all sample so that your gate is universal.