5844
Spermatozoa were exposed ex vivo to an alkylating agent ( methyl methanesulfonate ) before in vitro fertilization and DNA damage was assessed by the alkaline comet assay .
 Chemical: methyl methanesulfonate
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: methyl methanesulfonate