Medical Definition of horseradish peroxidase
: a peroxidase that occurs in the root of the horseradish (Armoracia lapathifolia of the mustard family), that produces a distinctive color when exposed to an appropriate solution, and that is used as a label for antibody-antigen complexes, as a cytochemical marker in immunohistochemical staining, and as a tracer to follow the course of individual neurons since it is transported by most neural pathways
Seen and Heard
What made you want to look up horseradish peroxidase? Please tell us where you read or heard it (including the quote, if possible).