In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: The extension of hemolysis is variable with erythrocyte samples , but 12 . 5 microM TAM induces total hemolysis of all tested suspensions .
### Output Text:
The extension of hemolysis is variable with erythrocyte samples , but 12 . 5 microM <span class="chemical">TAM</span> induces total hemolysis of all tested suspensions . 