Counterstains

Counterstains are histological reagents used to provide contrast by staining tissue components that are not specifically targeted by the primary stain, enhancing overall visualization under a microscope.

In immunohistochemistry (IHC) or immunofluorescence (IF), counterstains such as hematoxylin (for nuclei) or fluorescent DNA dyes help identify cellular structures and provide context for interpreting antigen-specific signals. They are essential for distinguishing target localization within complex tissue architecture.