Systematic workflow for Cell IDx UltraPlex. Step 1: A cocktail of primary antibodies, previously conjugated to unique hapten tags, is incubated with the tissue sections. Step 2: A cocktail of fluorescently labeled secondary antibodies, specific to the intended primary antibody’s hapten tag, is used to detect the localization of the primary antibody (Modified from “UltraPlex Technology”, by Cell IDx, Inc., [https://cellidx.com/technology/technology]. Copyright 2016–2019 by Cell IDx. Reprinted with permission)