Grade | Cytotoxicity/Reactivity | Description of Cytotoxicity/Reactivity Zone |
---|---|---|
0 | None | No detectable zone around or under specimen |
1 | Slight | Some malformed or degenerated cells |
2 | Mild | Zone limited to area under specimen |
3 | Moderate | Zone extends 0.5 to 1.0 cm beyond specimen |
4 | Severe | Zone extends greater than 1.0 cm beyond specimen but does not involve entire dish |