AEC (Aminoethyl carbazole) is one of the most used chromogens for immunohistochemistry (IHC) using horseradish peroxidase (HRP). HRP catalyzes the formation of a red precipitate from AEC.

The AEC is easy to use, simply incubate the slides for 5-10 minutes in a humid chamber at room temperature. The appearance of the staining can be followed by observation under microscope.

Since AEC is soluble in alcohol, samples should not be dehydrated after staining.

Slides can be mounted using an aqueous mounting medium (Simpo-Mount, NeoMount ...).

AEC can be used as a contrast stain with tissue pigments or for multiple labeling with other chromogens.