Preparation: Tissue samples are prepared, typically by fixing and embedding them in paraffin. Hybridization: Probes that are complementary to the target nucleic acid sequences are introduced. These probes are often labeled with digoxigenin or biotin. Detection: After hybridization, the probes are detected using an enzyme-labeled antibody. Common enzymes used include horseradish peroxidase (HRP) or alkaline phosphatase. Silver Enhancement: The enzyme catalyzes a reaction that deposits metallic silver, which can be seen as a black precipitate under a microscope.
