Why are basic conditions (pH ~9) important for the first reaction in Edman degradation?

• A. They facilitate the reaction of phenyl isothiocyanate with the N-terminal amino acid.
• B. They are necessary for the action of trifluoroacetic acid.
• C. They help in cleaving the peptide chain.
• D. They stabilize the PTH amino acid for identification.

Answer: (A)