41043
Carrel started an experiment on 17 January 1912 , where he placed tissue cultured from an embryonic chicken heart in a stoppered Pyrex flask of his own design .
 Carrel, Pyrex
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Carrel, Pyrex