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Peptide reactivity was measured by monitoring unreacted peptides with UV - Vis spectrophotometer using 5 , 5 ' - dithiobis - 2 - nitrobenzoic acid as a detection reagent for the free thiol group of cysteine - containing peptide or fluorometer using fluorescamine (TM) as a detection reagent for the free amine group of lysine - containing peptide .
 Chemical: 5 , 5 ' - dithiobis - 2 - nitrobenzoic acid; Chemical: thiol; Chemical: cysteine; Chemical: fluorescamine; Chemical: lysine
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: 5 , 5 ' - dithiobis - 2 - nitrobenzoic acid; Chemical: thiol; Chemical: cysteine; Chemical: fluorescamine; Chemical: lysine