Final answer:
HorseRadish Peroxidase (HRP) is used in the medical testing/ELISA lab for labeling antibodies. Its purpose is to catalyze a colorimetric reaction, indicating the presence of a specific antigen.
Step-by-step explanation:
In the medical testing/ELISA lab, the purpose of HorseRadish Peroxidase (HRP) is to label antibodies. In ELISA, a primary antibody captures the antigen, and then a secondary antibody conjugated with HRP is added. HRP catalyzes the conversion of a colorless substrate into a colored product, indicating the presence of the specific antigen. This colorimetric reaction helps in detecting and quantifying the antigen of interest.