O-phthalaldehyde: fluorogenic detection of primary amines in the picomole range. Comparison with fluorescamine and ninhydrin.

Abstract

O-Phthalaldehyde, in the presence of 2-mercaptoethanol, reacts with primary amines to form highly fluorescent products. Picomole quantities of amino acids, peptides, and proteins can be detected easily. o-Phthalaldehyde is five to ten times more sensitive than fluorescamine and is soluble and stable in aqueous buffers.