Fluorescamine is a spiro compound

Spiro compound

A spiro compound is a bicyclic organic compound with rings connected through just one atom. The rings can be different in nature or identical. The connecting atom is also called the spiroatom, most often a quaternary carbon...

 that is not fluorescent itself, but reacts with primary amines to form highly fluorescent products. It hence has been used as a reagent for the detection of amine

Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

s and peptide

Peptide

Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...

s. 1-100µg of protein and down 10pg protein can be detected . This method is found to suffer of high blanks resulting of high rate of hydrolysis due to used excess concentration. Alternative methods are based on ortho-Phthalaldehyde (OPA)

Phthalaldehyde

o-Phthalaldehyde or ortho-phthalaldehyde is the chemical compound with the formula C6H42. Often abbreviated OPA, the molecule is a dialdehyde, consisting of two formyl groups attached to adjacent carbon centres on a benzene ring...

, Ellman's reagent (DTNB)

Ellman's reagent

Ellman's reagent is a chemical used to quantify the number or concentration of thiol groups in a sample.-Preparation:...

 and epicocconone.