What is "iodoacetic acid"

n. (context organic compound English) The iodinated derivative of acetic acid CH₂I-COOH that is used in organic synthesis, and in protein sequencing

Iodoacetic acid is a derivative of acetic acid. It is a toxic compound, because, like many alkyl halides, it is an alkylating agent. It reacts with cysteine residues in proteins. It is often used to modify SH-groups to prevent the re-formation of disulfide bonds after the reduction of cystine residues to cysteine during protein sequencing.