Methylene blue (Basic Blue 9) is a guanylyl cyclase (sGC), monoamine oxidase A (MAO-A) and NO synthase (NOS) inhibitor. Methylene blue is a vasopressor and is often used as a dye in several medical procedures. Methylene blue through the nitric oxide syntase/guanylate cyclase signalling pathway to reduce prepulse inhibition. Methylene blue is a REDOX cycling compound and able to cross the blood-brain barrier. Methylene blue is a Tau aggregation inhibitor. Methylene Blue is a photosensitizer and redox agent. Methylene blue reduces cerebral edema, attenuated microglial activation and reduced neuroinflammation^[1][2][3][4].

Guanylyl cyclase (sGC)^[1].
Monoamine oxidase A (MAO-A)^[1].
NO synthase (NOS)^[1]

Methylene blue (Basic Blue 9) (4.5 μM; BV2 microglia) alters the immune profile of LPS-activated BV2 microglia and decreases the level of CD14, IL-1β, TNF-α, and CCL2 mRNA^[3].
1. Sample treatment:
1.1 For paraffin sections: dewax and rehydrate as usual.
1.2 For frozen sections: distilled water for 2 min.
1.3 For cultured cells: Fix with 4% paraformaldehyde. Wash with distilled water for 2 min. Replace with fresh distilled water and wash for another 2 min.
2. Methylene blue staining
2.1 Stain with 0.1% Methylene blue for 2 min.
2.2 Wash thoroughly with distilled water, observe and take photos.
2.3 Staining results:
Tissue or cells: blue

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

* 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, 1 year; -20°C, 6 months. When stored at -80°C, please use it within 1 year. When stored at -20°C, please use it within 6 months.

* Note: If you choose water as the stock solution, please dilute it to the working solution, then filter and sterilize it with a 0.22 μm filter before use.

• [1]. Klamer D, et, al. Phencyclidine-induced behaviour in mice prevented by methylene blue. Basic Clin Pharmacol Toxicol. 2004 Feb;94(2):65-72.  [Content Brief]

  [2]. Hochgräfe K, et, al. Preventive methylene blue treatment preserves cognition in mice expressing full-length pro-aggregant human Tau. Acta Neuropathol Commun. 2015 May 10;3:25.  [Content Brief]

  [3]. Fenn AM, et, al. Methylene blue attenuates traumatic brain injury-associated neuroinflammation and acute depressive-like behavior in mice. J Neurotrauma. 2015 Jan 15;32(2):127-38.  [Content Brief]

  [4]. Kalaitzakis D, et al. Methylene Blue as a Photosensitizer and Redox Agent: Synthesis of 5-Hydroxy-1H-pyrrol-2(5H)-ones from Furans. Angew Chem Int Ed Engl. 2015 May 18;54(21):6283-7.  [Content Brief]