Should I increase the time of tyramide development for thick tissue sections?

We do not have any firsthand information about whether increasing tyramide incubation time will improve staining for thicker sections. We have tested tyramide on slide-mounted cryosections that are 10 um thick. Published protocols for 40 um floating sections recommend performing the tyramide development step for 15 minutes at room temperature.

If you are using free-floating sections, generally all incubation steps (permeabilization, antibody incubation, and washing) are longer than for sections on slides. The tyramides are small molecules and should penetrate tissue more rapidly than antibody conjugates, but you may wish to test a longer incubation time to allow the buffer to penetrate the tissue.