Merocyanin 540 

Merocyanin 540 is a fluorescent membrane probe that selectively stains the membranes of a wide variety of electrically excitable cells, but not those of nonexcitable cells (Ex/Em: 540/580 nm)^[1][2].

Operating Instructions (The following represents our recommended protocol. This protocol serves solely as a reference guide; specific procedures should be adjusted according to your actual requirements)^[1].
1. Cell Labeling:
1) Wash the adherent cell monolayer using isotonic saline (which may or may not contain 1–5 mM CaCl₂) or an isotonic sucrose solution (0.25 M) buffered with 5 mM Tris-Cl (pH 7.4).
2) Suspend the cells in an appropriate buffer, add Merocyanin 540 (to a concentration of 1.6 x 10^-5 M), and incubate for 10 minutes at room temperature under ambient light conditions.
3) Wash the cells thoroughly, then observe them using a fluorescence microscope.
2. Protozoan Samples:
1) Pipette 0.05 mL of washed culture medium (containing 100–200 protozoa) onto a microscope slide.
2) Add Merocyanin 540 to achieve a final concentration of 1.0–10 μg/mL.
3) Observe the cells using a fluorescence microscope.
3. Single-Cell Suspensions or Tissue Sections:
1) Incubate the single-cell suspension or tissue section with Merocyanin 540 (at a concentration of 1.75–5.25 x 10^-5 M), then observe the sample using a fluorescence microscope, following the detection method outlined for adherent cells.

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

569.67

C₂₆H₃₂N₃NaO₆S₂

62796-23-0

Solid

Dark purple to black

580

540

O=C1/C(C(N(CCCC)C(N1CCCC)=S)=O)=C/C=C/C=C2OC3=C(N/2CCCS(=O)(O[Na])=O)C=CC=C3

Room temperature in continental US; may vary elsewhere.

4°C, protect from light, stored under nitrogen

*In solvent : -80°C, 6 months; -20°C, 1 month (protect from light, stored under nitrogen)

* 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 (protect from light, stored under nitrogen). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

• [1]. Easton TG, et al. Merocyanine 540 as a fluorescent probe of membranes: staining of electrically excitable cells. Cell. 1978 Mar;13(3):475-86.  [Content Brief]

  [2]. Lagerberg JW, et al. Factors affecting the amount and the mode of merocyanine 540 binding to the membrane of human erythrocytes. A comparison with the binding to leukemia cells. Biochim Biophys Acta. 1995 May 4;1235(2):428-36.  [Content Brief]