Why is an HRP conjugated secondary antibody used in western blotting?

Western blotting is one of the most sensitive techniques that’s used for detecting specific proteins. Using HRP conjugated secondary antibody amplifies the signal and increases sensitivity considerably, making it easier to detect the protein of interest in a complex protein mixture. This increased sensitivity is because HRP (Horseradish peroxidase) catalyzes the chemical reaction for generating a recordable signal in the form of light.

Using a HRP conjugated secondary antibody offers a distinct advantage over using a conjugated primary antibody in applications such as western blotting where high specificity and low background noise are critical to protein detection. This is especially important when the target molecule is present at low levels or when the sample volume is limited.