FlowJo v11 now includes an option to correct compensation / unmixing matrices by applying a direct parameter-parameter adjustment. This can be particularly helpful for spectral unmixing matrices for which adjustments made to the interaction between a pair of parameters is more direct and easier conceptually then to make parameter-to-detector corrections, when many detectors may impact the output.
Figure 1 Direct adjustment to the spillover matrix
Figure 1 shows the outcome of editing an acquisition matrix and selecting Compensation / Spillover. The hierarchy shows the copied acquisition matrix selected, with the name appended with ‘Edit’. Over the matrix display the orange box is drawn around the editing selection. Notice that with Spillover selected the matrix shows columns of parameters, and rows of detectors. This matrix will be number of parameters by all detectors.
Figure 2 Adjustment by correction matrix
Figure 3 shows the outcome of selecting the correction matrix. The rows and columns are both now parameters, so you can adjust specific interactions. The default value for all combinations is 0%, meaning no adjustment. The diagonals are a comparison of a parameter to itself and is listed as 100%. The max value for all other combinations is 100% meaning that all of the signal from the parameter on the row is attributed to the parameter on the column. Figure 3 shows some example interactions. Note that the plot that will be affected by editing a value in the correction matrix is highlighted with a blue box, and vice versa.
Figure 3 Various correction values applied to a pair of parameters