22830
After 18 h incubation with 0 . 5 mu M Py3MeO - TBPo and subsequent red light irradiation ( 3 . 6 J / cm ( 2 ) ) , a high number of cells die by apoptosis , as evaluated by morphological alterations , immunofluorescent relocalization of Bax from cytosol to mitochondria , and TUNEL assay .
 Py3MeO - TBPo
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 Py3MeO - TBPo