Thermo Scientific Pierce Fluoraldehyde Crystals are o-phthalaldehyde (OPA), a highly sensitive fluorescent derivatization reagent for peptide or amino acid detection and quantitation in HPLC.

Features of Fluoraldehyde o-Phthalaldehyde Crystals:

• For pre- or post-column amino acid derivatization for fluorescent detection and quantitation
• Reacts with all primary amine-containing analytes to yield fluorescent derivatives (ex/em = 340nm/455nm)
• Provides an accurate measure of both composition and absolute protein-peptide content
• Ideal for work with recombinant proteins and synthetic peptides
• Can be used for fluorescent protein or peptide assay
• Can be prepared as a stable aqueous solution in borate (see instructions)

Fluoraldehyde Crystals are a specially purified, fluorogenic-grade preparation of o-phthalaldehyde (OPA). This amine-reactive compound is primarily used for high-sensitivity, fluorescent detection of primary amines, including amino acids, peptides, proteins and polyamines in pre- or post-column chromatographic effluents.

Reagent Properties:
• Alternative names: Fluoraldehyde Crystals, OPA
• Chemical name: ortho-Phthalaldehyde
• Reactive toward: Primary amines (—NH2)
• Chemical formula: C₈H₆O₂
• CAS number: 643-79-8
• Molecular weight: 134.12
• Form: Pale yellow, free-flowing crystals

For even greater sensitivity, use a combination of OPA and Fmoc-Chloride with automated pre-column derivatization to detect both primary and secondary amines. With this application, primary amino acids are first derivatized with OPA and then remaining secondary amino acids are reacted with Fmoc-Chloride, resulting in extraordinary amino acid detection sensitivity and accuracy (see Lindroth and Mopper, 1979; Lee and Drescher, 1979).