2698
It is important to prepare the slices in a cold preservation solution , to prepare the slices at a correct thickness , and to incubate the slices in a system where the slice rotates in out of the oxygen atmosphere and medium .
 Chemical: oxygen
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: oxygen