Paraffin-embedded sections are first dewaxed to replace the wax with water; this is because most staining solutions are aqueous.
Dewaxing is usually followed by an antigen-retrieval method, which unmasks antigens that have been obscured during the fixation process.
Next, depending upon the type of antibodies that will be used, a series of blocking steps take place that serve to minimize non-specific interactions of the antibody and block endogenous enzymes that can result in false positives.
After blocking, the sections are incubated in antibodies; this incubation can be in directly conjugated primaries or can consist of sequential incubations in both primary and secondary antibodies (fluorescent or enzyme-linked).
If an enzyme-linked secondary is used, a further incubation in substrate will be required, otherwise the sections can be mounted and imaged.