Modern immunodetection methods are based on enzyme-linked detection, utilizing secondary antibodies covalently bound to enzymes such as horseradish peroxidase (HRP) or alkaline phosphatase (AP). The conjugated enzyme catalyzes the degradation of specific substrates, resulting in signal generation. Three types of substrates are commonly used:
As well as detection with fluorophore-labeled secondary antibodies. Immobilon PVDF membranes have been tested for compatibility with all commercially available chromogenic and chemiluminescent substrates.