Description

Fluorescein-5-Thiosemicarbazide is a reactive fluorescent dye derivative, widely used as a critical labeling reagent for biomolecules. Its core value lies in the thiosemicarbazide functional group, which enables highly specific conjugation to aldehydes and ketones under mild conditions, while the fluorescein moiety provides strong, pH-sensitive fluorescence for detection. This compound is essential for researchers and manufacturers in the fields of bioanalytical chemistry, diagnostics, and materials science who require precise fluorescent tagging for imaging, assay development, and sensor fabrication.

Application

• Bioconjugation and Labeling: Selective tagging of glycoproteins, polysaccharides, and other carbonyl-containing biomolecules for fluorescence microscopy and flow cytometry.
• Diagnostic Assay Development: Used as a fluorescent probe in the development of ELISA, lateral flow assays, and other immunoassays for high-sensitivity detection.
• Materials Science & Sensor Fabrication: Functionalization of nanoparticles, polymers, and surfaces to create fluorescent sensors for pH, metal ions, or specific analytes.
• Pharmaceutical Research: Tracing and studying drug delivery mechanisms by conjugating to drug molecules or carrier systems.
• Glycobiology Studies: Specific labeling of oxidized glycans for analysis via gel electrophoresis or liquid chromatography.
• Chemical Biology Probes: Synthesis of activity-based probes to visualize enzyme activity or protein function in live cells.

Basic Information

Product Name	Fluorescein-5-Thiosemicarbazide
CAS No.	76863-28-0
Molecular Formula	C21H15N3O5S
Molecular Weight	421.43 g/mol
Synonyms	5-Fluoresceinthiosemicarbazide; Fluorescein 5-thiosemicarbazone; 5-(Thiosemicarbazido)fluorescein; 3',6'-Dihydroxyspiro[2-benzofuran-3,9'-xanthene]-5-carbothioic acid, 1'-hydrazide; 5-FTSC; F5T; Fluorescein isothiocyanate hydrazide analog; Reactive Fluorescein Hydrazide
EINECS	Contact for details

Quality Control

Our Fluorescein-5-Thiosemicarbazide is manufactured under strict quality management systems. Each batch undergoes rigorous analytical testing, including HPLC for purity and identity confirmation via spectroscopic methods, to ensure it meets the high standards required for research and diagnostic applications. A comprehensive Certificate of Analysis (COA) detailing purity, absorbance/fluorescence properties, and performance in conjugation 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 for long-term stability. The product is light-sensitive (store away from light) and may be hygroscopic. 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%
Absorption Max (λmax)	~490 nm
Emission Max	~515 nm
Solubility	Soluble in DMSO, DMF; sparingly soluble in water
Loss on Drying	≤ 2.0 %

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