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: METHODS : We sent a questionnaire concerning complications of indocyanine green to 32 institutions in Japan , which were selected on the basis of the client list from the Topcon Company , which manufactures the indocyanine green fundus camera .
### Output Text:
METHODS : We sent a questionnaire concerning complications of <span class="chemical">indocyanine green</span> to 32 institutions in Japan , which were selected on the basis of the client list from the Topcon Company , which manufactures the <span class="chemical">indocyanine green</span> fundus camera . 