[hell0joe]

My textbook states that dansyl chloride reacts with primary amines to form dansylated polypeptides (for the process of protein sequencing).

Would there be a problem if there was a lysine residue in the polypeptide, since dansyl chloride would also react with the amino group of lysine as well?

[AWK]

Amino group of lysine is also reactive.

[Babcock_Hall]

The same problem shows up in the use of fluorodinitrobenzene.