12551
Two subunits of phycocyanin namely alpha - phycocyanin ( 18 . 4 kDa ) and beta - phycocyanin ( 21 . 3 kDa ) were found to remain from the original mixtures after being extracted , based on SDS - PAGE analysis , clearly demonstrating that this process can stably extract phycocyanin and is not affected by extraction solvent , temperature , etc .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
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