Description

Fluorescein 6-Isothiocyanate (CAS NO 18861-78-4) is a vital fluorescent labeling reagent widely used for the covalent conjugation of biomolecules. This compound matters because it provides a bright, stable fluorescent tag, enabling sensitive detection and analysis in complex biological systems. It is primarily needed by researchers and manufacturers in the biotechnology, pharmaceutical, and diagnostic industries for applications such as antibody labeling, protein tracking, and cellular imaging.

Application

• Fluorescent Antibody Labeling: Conjugation to antibodies for use in immunofluorescence (IF), flow cytometry (FACS), and immunohistochemistry (IHC).
• Protein and Peptide Tagging: Covalent attachment to proteins, peptides, and other amine-containing biomolecules for tracking and quantification.
• Cellular and Tissue Imaging: Preparation of fluorescent probes for visualizing cellular structures and processes in microscopy.
• Diagnostic Assay Development: Key reagent in the manufacture of fluorescent-based diagnostic kits and biosensors.
• Bioconjugation Research: A standard tool in research laboratories for developing novel bioanalytical methods and studying biomolecular interactions.
• High-Throughput Screening (HTS): Used to label targets in drug discovery and biochemical screening assays.

Basic Information

Product Name	Fluorescein 6-Isothiocyanate
CAS No.	18861-78-4
Molecular Formula	C21H11NO5S
Molecular Weight	389.38 g/mol
Synonyms	6-Fluorescein Isothiocyanate; 6-FITC; FITC Isomer I; Fluorescein Isothiocyanate Isomer I; 5(6)-Isothiocyanatofluorescein; 5(6)-FITC; 5-Isothiocyanatofluorescein; 5-FITC; 2-(6-Isothiocyanato-3-oxo-3H-xanthen-9-yl)benzoic Acid
EINECS	242-630-9

Quality Control

Our Fluorescein 6-Isothiocyanate is produced under strict quality management systems. Each batch undergoes rigorous analytical testing to ensure high purity and consistent performance for sensitive bioconjugation applications. Certificates of Analysis (COA) with detailed HPLC purity data are provided to guarantee compliance with research and in-vitro diagnostic grade standards.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at 2-8°C. This product is hygroscopic (moisture-sensitive) and light-sensitive. Allow the vial to equilibrate to room temperature in a desiccator before opening to prevent moisture condensation.

Specification

Item	Specification
Appearance	Orange to red powder
Identification (IR)	Conforms to structure
Purity (HPLC)	≥ 95.0% (Isomer I)
Total FITC Isomers (HPLC)	≥ 98.0%
Absorption (λ max)	490 - 500 nm
Emission (λ max)	515 - 525 nm
Solubility	Soluble in DMSO, DMF
Moisture Content (KF)	≤ 2.0%

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