Fluorescein, scientifically identified as Spiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3-one,3',6'-dihydroxy with CAS number 2321-07-5, is a chemical compound celebrated for its exceptional fluorescent properties. Understanding its core scientific attributes is key for researchers and chemists looking to harness its full potential in various advanced applications. When you buy Fluorescein, you are acquiring a molecule designed for precision and visibility.

At its heart, Fluorescein is a fluorophore, meaning it absorbs light at a specific wavelength and re-emits it at a longer wavelength. Its spectral characteristics are well-defined: it exhibits peak excitation in the blue light spectrum, typically around 494 nm, and emits strongly in the green spectrum, with an emission maximum near 521 nm. This distinct spectral profile makes it highly detectable and invaluable for applications requiring sensitive fluorescence detection.

The physical form of Fluorescein as a white powder is convenient for handling and formulation. Its solubility is a critical factor for its practical use. While largely insoluble in water, it readily dissolves in dilute alkaline solutions, alcohols, and other organic solvents like acetone and DMSO. This varied solubility allows chemists to tailor its use in different solvent systems, whether for preparing solutions for microscopy, diagnostic assays, or as a reactant in chemical synthesis.

Chemically, Fluorescein possesses a pKa of approximately 6.4, indicating that its fluorescence intensity and spectral properties can be pH-dependent. This characteristic can be both a challenge and an advantage, allowing for pH-based sensing applications. Manufacturers focus on producing Fluorescein with high purity (often exceeding 98% or 99%) to ensure reproducible results and minimize interference from impurities in sensitive assays.

For those looking to buy Fluorescein, understanding these properties is crucial for selecting the right grade and supplier. Whether used as a direct fluorescent label, a precursor for more complex fluorescent probes, or as a tracer in industrial processes, the scientific integrity of Fluorescein (CAS 2321-07-5) is paramount. Reputable manufacturers and suppliers, especially those based in China, offer this compound with detailed technical data to support its use in cutting-edge scientific endeavors.