Table 1 Immunostaining intensity classification
Characterization | Symbolism | Staining intensity | Stained specimen |
|---|---|---|---|
Negative | 0 | No staining reaction |  < 20% |
Weakly positive | 1 | Weak staining intensity | 20–50% |
Moderate positive | 2 | Moderate staining intensity | 51–80% |
Strongly positive | 3 | Strong staining intensity |  > 80% |