Description

2-[(5-Fluoresceinyl)Aminocarbonyl]Ethyl Methanethiosulfonate is a high-purity, bifunctional chemical reagent designed for advanced bioconjugation and labeling applications. Its core value lies in its ability to specifically and covalently modify thiol groups (-SH) on proteins, peptides, and other biomolecules while introducing a highly fluorescent fluorescein tag for detection. This compound is essential for researchers and manufacturers in the fields of biochemical research, diagnostic assay development, and pharmaceutical analysis who require precise, site-specific fluorescent labeling.

Application

• Site-Specific Protein Labeling: Covalently attaches a fluorescein reporter to cysteine residues for structural studies, fluorescence resonance energy transfer (FRET), and protein interaction analysis.
• Diagnostic Probe Synthesis: Used in the development of fluorescent probes and conjugates for immunoassays (ELISA, Western Blot) and flow cytometry.
• Bioconjugation for Drug Delivery: Facilitates the creation of fluorescently tagged antibody-drug conjugates (ADCs) or nanoparticle systems for tracking and research.
• Biomolecular Imaging: Enables the fluorescent labeling of peptides, oligonucleotides, or other biomolecules for live-cell or in vitro imaging applications.
• Sensor Development: Acts as a key component in constructing biosensors where thiol binding triggers a fluorescent signal.
• Quality Control in Biopharma: Employed in analytical methods to label and quantify proteins or assess drug conjugate integrity.

Basic Information

Product Name	2-[(5-Fluoresceinyl)Aminocarbonyl]Ethyl Methanethiosulfonate
CAS No.	351330-42-2
Molecular Formula	C25H19NO8S2
Molecular Weight	525.55 g/mol
Synonyms	Fluorescein-5-maleimide Thiol-Reactive Probe; 5-Fluorescein Maleimide; 5-FAM Maleimide; Fluorescein Maleimide; 2-[(5-Fluoresceinyl)Aminocarbonyl]Ethyl Methanesulfonothioate; MTS-Fluorescein; Fluorescein-C2-Maleimide; Fluorescein-5-C2-Maleimide
EINECS	Contact for details

Quality Control

Our 2-[(5-Fluoresceinyl)Aminocarbonyl]Ethyl Methanethiosulfonate is manufactured under strict quality systems to ensure batch-to-batch consistency and high performance. Each lot undergoes comprehensive analytical testing, including HPLC for purity and identity confirmation (NMR, IR). We provide a detailed Certificate of Analysis (COA) with every shipment, documenting the purity, impurity profile, and other critical parameters to support your research and compliance needs.

Storage

Preserve in a tightly closed container, protected from light. Store at -20°C or below under desiccant. This product is hygroscopic (moisture-sensitive) and light-sensitive. Allow the vial to equilibrate to room temperature in a desiccator before opening to prevent condensation and hydrolysis.

Specification

Item	Specification
Appearance	Orange to red solid
Identification (HPLC)	Conforms
Identification (NMR)	Conforms
Purity (HPLC)	≥ 95.0%
Solubility	Soluble in DMSO, DMF
Extinction Coefficient	~68,000 cm⁻¹M⁻¹ at 494 nm (pH 9.0)
Fluorescence	Ex/Em ~494/518 nm (pH 9.0)

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.