Description

Fluorescein Isothiocyanate Isomer I is a high-purity, reactive fluorescent dye derivative essential for labeling and detection in advanced biochemical applications. Its specific isomer configuration ensures optimal conjugation efficiency and fluorescence yield, making it a critical reagent for researchers and manufacturers. This product is primarily utilized in the biotechnology, pharmaceutical, and diagnostic industries for applications such as antibody labeling, flow cytometry, and fluorescence microscopy.

Application

• Fluorescent Antibody Conjugation: Primary reagent for covalently labeling antibodies (IgG, IgM) and other proteins for immunofluorescence assays (IFA).
• Flow Cytometry & Cell Sorting (FACS): Used to tag cell surface markers or intracellular proteins for analysis and isolation of specific cell populations.
• Fluorescence Microscopy & Imaging: Provides a bright, photostable green fluorescent tag for visualizing cellular structures and biomolecular localization.
• Diagnostic Kit Manufacturing: A key component in the production of lateral flow assays, ELISA kits, and other in-vitro diagnostic (IVD) devices.
• Biomolecular Probes: Synthesis of fluorescent probes for studying enzyme activity, receptor binding, and nucleic acid interactions.
• Protein & Peptide Sequencing: Historically used in Edman degradation for N-terminal amino acid analysis.

Basic Information

Product Name	Fluorescein Isothiocyanate Isomer I
CAS No.	3326-32-7
Molecular Formula	C21H11NO5S
Molecular Weight	389.38 g/mol
Synonyms	FITC Isomer I; 5-FITC; Fluorescein 5-isothiocyanate; 5-Isothiocyanatofluorescein; Isomer I of Fluorescein Isothiocyanate; FITC (Isomer I); Reactive Fluorescein Derivative; Fluorescein-5-isothiocyanate
EINECS	222-035-5

Quality Control

Our Fluorescein Isothiocyanate Isomer I is manufactured under strict quality management systems to ensure batch-to-batch consistency and high performance. Each lot is subjected to rigorous analytical testing, including HPLC for purity and isomer content, to meet the stringent requirements of research and diagnostic applications. A comprehensive Certificate of Analysis (COA) detailing identity, purity, and performance specifications is provided with every shipment.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry place at 2-8°C. The product is hygroscopic (moisture-sensitive) and light-sensitive; prolonged exposure to ambient conditions or light will degrade performance. For long-term stability, store desiccated under inert atmosphere.

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 Maximum	490 - 495 nm
Emission Maximum	515 - 520 nm
Moisture Content (KF)	≤ 2.0%
Solubility	Soluble in DMSO, DMF; slightly soluble in acetone

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