Description

3',6'-Bis(Dimethylamino)-5-(Isothiocyanato)Spiro[Isobenzofuran-1(3H),9'-[9H]Xanthen]-3-One is a high-purity, reactive fluorescent dye derivative, widely recognized as a key labeling reagent in advanced biochemical research. Its core value lies in its isothiocyanate (NCS) functional group, which enables stable covalent conjugation to primary amines under mild conditions, making it indispensable for creating highly specific fluorescent probes. This compound is primarily needed by research institutions, diagnostic kit manufacturers, and pharmaceutical developers working in flow cytometry, fluorescence microscopy, immunoassay development, and nucleic acid detection. The CAS number for this compound is 20746-54-7.

Application

• Fluorescent Antibody & Protein Labeling: Covalently tags antibodies, streptavidin, and other proteins for use in fluorescence-activated cell sorting (FACS), immunohistochemistry (IHC), and Western blotting.
• Nucleic Acid Probe Synthesis: Used to label oligonucleotides for fluorescence in situ hybridization (FISH) and real-time PCR applications.
• Cell Tracing & Viability Assays: Employed in the synthesis of cell-permeable dyes for long-term cell tracking, proliferation studies, and apoptosis detection.
• Diagnostic Reagent Manufacturing: A critical raw material in the production of fluorescent conjugates for clinical diagnostic assays and lateral flow tests.
• Biomarker Detection & Imaging: Facilitates the development of targeted imaging agents for research in oncology, immunology, and neuroscience.
• Material Science & Sensor Development: Incorporated into polymers and nanoparticles to create smart materials and chemical sensors with optical reporting capabilities.

Basic Information

Product Name	3',6'-Bis(Dimethylamino)-5-(Isothiocyanato)Spiro[Isobenzofuran-1(3H),9'-[9H]Xanthen]-3-One
CAS No.	20746-54-7
Molecular Formula	C25H19N3O3S
Molecular Weight	441.50 g/mol
Synonyms	5-Isothiocyanatofluorescein; FITC Isomer I; Fluorescein 5-Isothiocyanate; 5-FITC; Fluorescein Isothiocyanate Isomer I; 3',6'-Dihydroxy-5-isothiocyanatospiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3-one (deprotonated form); 5-(Isothiocyanato)fluorescein
EINECS	Contact for details

Quality Control

Every batch of our 3',6'-Bis(Dimethylamino)-5-(Isothiocyanato)Spiro[Isobenzofuran-1(3H),9'-[9H]Xanthen]-3-One is manufactured under strict quality management systems. We provide comprehensive analytical data to ensure the product meets the high standards required for sensitive life science applications. Certificates of Analysis (COA) detailing purity, isomer content, and performance in labeling reactions are available upon request. Our quality commitment supports compliance with ISO 13485 standards for diagnostic manufacturers.

Storage

Preserve in a tightly closed container, protected from light. For long-term stability, store desiccated at -20°C. Under these conditions, the product is typically stable for 24 months. 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 Content (HPLC)	≥ 90.0%
Water Content (KF)	≤ 1.0%
Labeling Performance	Conforms to reference

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