Octadecyl Rhodamine B chloride 

Octadecyl Rhodamine B chloride is an amphiphilic fluorescent probe with both membrane-binding ability and fluorescent properties, which easily forms aggregates in aqueous phase leading to self-quenching. Octadecyl Rhodamine B chloride can be used for cell membrane staining and further applied in membrane biology research. The maximum absorption/emission wavelengths of Octadecyl Rhodamine B chloride monomer in Triton X-100 are 565 nm/585 nm; the absorption peaks of aggregates in water are blue-shifted to 524 nm and 574 nm, with significantly quenched fluorescence^[1].

The reference procedures for using Octadecyl Rhodamine B chloride as a fluorescent probe are as follows^[1]:
1. Reagent and Model Membrane Preparation: Prepare a stock solution of Octadecyl Rhodamine B chloride (e.g., 1 mM in DMSO), and dilute it to a working concentration (0.44-4.4 µM) with a buffer containing 0.1% human serum albumin (HSA) (e.g., Tris) to avoid aggregation (critical aggregation concentration (CAC): 14 nM). Fabricate lipid bilayers of liquid-disordered phase (DOPC) and liquid-ordered phase (DSC, DOPC:SM:cholesterol = 1:1:1), and conjugate them to glass beads to form model membranes.
2. Membrane Binding and Real-Time Detection: Incubate the beads with Octadecyl Rhodamine B chloride (37°C, with stirring), and monitor fluorescence signals in real time by flow cytometry. Quantify the number of membrane-bound Octadecyl Rhodamine B chloride molecules using quantum dot-calibrated beads.
3. Fluorescence Analysis and Kinetic Modeling: Determine the self-quenching curve of Octadecyl Rhodamine B chloride (e.g., by adding Triton X-100 for dequenching), and analyze energy transfer efficiency using FRET technology. Fit the binding kinetics through mass action models to evaluate the effects of membrane structure on Octadecyl Rhodamine B chloride partitioning (e.g., differences in binding capacity and quenching degree).
Note: Maintain Octadecyl Rhodamine B chloride concentration below CAC to ensure monomeric state, optimize membrane binding kinetics using HSA as a carrier, and achieve quantitative analysis by integrating flow cytometry and spectroscopic techniques.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

731.49

C₄₆H₆₇ClN₂O₃

65603-19-2

Solid-Liquid Mixture

Pale purple to purple

578

556

[Cl-].O=C(OCCCCCCCCCCCCCCCCCC)C=1C=CC=CC1C=2C=3C=CC(=CC3[O+]=C4C=C(C=CC42)N(CC)CC)N(CC)CC

Room temperature in continental US; may vary elsewhere.

4°C, sealed storage, away from moisture and light

*In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture and light)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture and light). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

• [1]. Tione Buranda, et al. Real-time partitioning of octadecyl rhodamine B into bead-supported lipid bilayer membranes revealing quantitative differences in saturable binding sites in DOPC and 1:1:1 DOPC/SM/cholesterol membranes. J Phys Chem B. 2010 Jan 28;114  [Content Brief]