Recent dye development has made panel design a lot easier than it was a few years ago. In this talk we will look at how to characterize dyes especially using spectral flow cytometry, and how to predict performance. We will learn how to choose dyes based on a very simple matrix view to avoid spreading issues. Last, but not least, we will look into the new BD Research cloud online tool. Here we can design panels, even with automated help, and can learn everything about dye similarity and the new "HotSpot" matrix to predict problematic areas of unmixing dyes.Best,The Flow Cytometry Unit