41038
pBR322 is 4361 base pairs in length and contains the replicon of plasmid pMB1 , the ampR gene , encoding the ampicillin resistance protein ( source plasmid RSF2124 ) and the tetR gene , encoding the tetracycline resistance protein ( source plasmid pSC101 ) .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
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