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Fluoraldehyde OPA Reagent Solution

Ready-to-use solution for HPLC derivatization and fluorescent detection of amino acids.

Pierce Fluoraldehyde (OPA)

Thermo Scientific Pierce Fluoraldehyde OPA Reagent is a ready-to-use solution of o-phthalaldehyde, a fluorescent derivatization reagent for peptide or amino acid detection and quantitation in HPLC.

Fluoraldehyde Reagent Solution contains OPA (o-phthalaldehyde), which reacts with primary amines of amino acids, peptide and proteins to enable fluorescent detection and quantitation. The reagent that can be used as a protein or peptide assay reagent or as a pre- or post-column detection reagent for amino acid analysis (HPLC). Reaction of OPA with proteins and peptides yields linear results over a wide range of concentrations. The Fluoraldehyde Reagent Solution is supplied ready to use and enables fast quantitation of proteins or peptides in solution.


  • For pre- or post-column amino acid derivatization for fluorescent detection and quantitation
  • Reacts with all primary amine-containing analytes to yield fluorescent isoindole derivatives
  • 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
  • Pre-column derivatization mixtures can be injected into LC without any processing

Reagent Properties:

  • Formulation: 0.8mg/mL o-phthalaldehyde (OPA) in proprietary buffer, pH 10
  • Form: Clear, colorless to slightly yellow liquid
  • Reactive toward: Primary amines (–NH2)
  • Detection: Fluorescence (excitation/emission = 340nm/455nm)
  • Application: Pre- or post-column derivatization for detection by HPLC

Product Details:

Fluoraldehyde Reagent, o-Phthalaldehyde OPA Chemical structure of ortho-phthalaldehyde (OPA).Thermo Scientific Fluoraldehyde Reagent is a ready-to-use solution of 0.8mg/mL o-phthalaldehyde (OPA) in proprietary buffer, pH 10. Crystalline OPA is also available (Part No. 26015).

Linearity and sensitivity of phthalaldehyde OPA detection
Phthaldehyde (OPA) derivatization reaction. The rapid OPA-amine reaction in the presence of 2-mercaptoethanol yields an intense blue fluorescent product that has maximum excitation and emission wavelengths of 340 and 455nm, respectively. Thermo Scientific Fluoraldehyde Reagent is a ready-to-use solution that contains OPA and 2-ME.

Linearity and sensitivity of phthalaldehyde OPA detection
Excellent linearity and high sensitivity with ortho-phthalaldehyde (OPA) derivatization. Experiment with Thermo Scientific Fluoraldehyde Reagent Solution shows excellent linear response, whether in the 2500 or 200 picomole range.

OPA performance with new and old Fluoraldehyde Reagent Solution
Outstanding shelf life. Comparison of fluorescence response of selected amino acids after reaction with new and one-year-old Fluoraldehyde Reagent Solutions. Peak height and quality are nearly as good with the older solution.


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Ordering Information
Product # Description Pkg. Size Instructions MSDS CofA Price
26025 Fluoraldehyde Reagent Solution
Formulation: o-Phthalaldehyde; 0.8mg/mL solution (pH 10)
Sufficient For: Use neat (undiluted) as a pre- or post-column detection reagent in HPLC
945mL Product Instructions for product #26025 Fluoraldehyde Reagent Solution MSDS for product #26025 Fluoraldehyde Reagent Solution Certificate of Analysis for product #26025 Fluoraldehyde Reagent Solution $222.00

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Instructions | MSDS | CofA
Product Instructions | MSDS | CofA  

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