Basis of differentiation | Regressive staining | Progressive staining |
Definition | Is a type of staining in which the tissue is intentionally over-stained and then de-stained or differentiated until the it reaches the desired endpoint | Is a type of staining in which the tissue is left in the staining solution just long enough to reach the desired endpoint |
Concentration of the stain | Highly concentrated | Less concentrated |
Background stain | Does not produce background staining | Produces background staining |
Staining of non-cellular components | Stains non-cellular components | Does not stain non-cellular components |
Coloring of the cytoplasm | Over-stains the cytoplasm | Cytoplasm is less stained |
Differentiation step (excess stain removal) | Contains a differentiation step | Does not contains a differentiation step |
Differentiation in a dilute acid alcohol | Required | Not required |
Use of eosin | Uses eosin to stain non-cellular materials | Does not use eosin |
Haematoxylin concentration | Regressive haematoxylins are more concentrated | Progressive haematoxylins are less concentrated |
Commonly used stains |
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Speed of process | Is a fast process | Is a gradual process |