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 morphological analysis of the kidneys included a semi - quantitative scoring system analysing the degree of striped fibrosis , subcapsular fibrosis and the number of basophilic tubules , plus an additional stereological analysis of the total grade of fibrosis in the cortex stained with Sirius Red .
### Output Text:
The morphological analysis of the kidneys included a semi - quantitative scoring system analysing the degree of striped fibrosis , subcapsular fibrosis and the number of basophilic tubules , plus an additional stereological analysis of the total grade of fibrosis in the cortex stained with Sirius Red . 