4786
First report of the use of a saxitoxin - protein conjugate to develop a DNA aptamer to a small molecule toxin .
 Chemical: saxitoxin
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: saxitoxin 
Answer:
 Chemical: saxitoxin