The Fluorescein Arsenical Hairpin Binder (FlAsH) method is presented for fluorescence labeling of proteins in living cells. Labeling proteins with the membrane-permeant fluorogenic biarsenical dye fluorescein arsenical hairpin binder-ethanedithiol (FlAsH-EDT2). The membrane-permeant fluorogenic biarsenicals FlAsH-EDT2 and ReAsH-EDT2 can be prepared in good yields by a straightforward two-step procedure from the inexpensive precursor dyes fluorescein and resorufin.Melting Point:169-172°C (dec.)Solubility:Chloroform (Slightly), Methanol (Slightly, Heated)Method for Determining Identity: Proton NMR (CDCl3) Spectroscopic and Mass Spectrometric AnalysisAtmosphere: Inert gasTLC Conditions: As Reported Elemental Analysis: As ReportedStorage and Stability:May be stored at RT for short-term only. Long-term storage is recommended at -20°C. For maximum recovery of product, centrifuge the original vial prior to removing the cap. Light, temperature, and moisture sensitive. Store under inert atmosphere.Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological. Toxicity and Hazards: All products should be handled by qualified personnel only, trained in laboratory procedures.
