21695
3 - ( 4 , 5 - Dimethylthiazol - 2 - yl ) - 2 , 5 - diphenyl tetrazolium ( MTT ) assay was performed to assess cytotoxicity .
 3 - ( 4 , 5 - Dimethylthiazol - 2 - yl ) - 2 , 5 - diphenyl tetrazolium, MTT
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 3 - ( 4 , 5 - Dimethylthiazol - 2 - yl ) - 2 , 5 - diphenyl tetrazolium, MTT