14448
Additionally , the cloning vectors may contain colour selection markers , which provide blue / white screening ( alpha-factor complementation ) on X-gal medium .
 location: X-gal
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: X-gal 
Answer:
 location: X-gal