Methylene Blue, chemically designated as methylthioninium chloride, is a synthetic thiazine dye extensively utilized as a redox-active probe in biochemical, cellular, and molecular research systems. Its physicochemical properties enable reversible electron transfer, making it a widely studied compound in investigations involving mitochondrial electron transport, oxidative–reductive balance, and intracellular redox cycling.

In laboratory research contexts, methylene blue has been employed as a staining reagent, redox indicator, and experimental modulator of mitochondrial bioenergetics. Contemporary preclinical research has expanded its use into experimental models examining mitochondrial signaling, oxidative stress regulation, and intracellular energy dynamics under controlled in-vitro and in-vivo animal conditions.

Source: PubChem

Molecular Formula: C₁₆H₁₈ClN₃S
Molecular Weight: 319.85 g/mol
PubChem CID: 6099
CAS Number: 61-73-4
Synonyms: Methylthioninium chloride, Basic Blue 9, Solvent Blue 8

Methylene blue functions as a reversible redox-active compound capable of accepting and donating electrons within biological systems. Its redox cycling between oxidized methylene blue and reduced leucomethylene blue allows participation in electron transport processes independent of oxygen availability.

In experimental systems, methylene blue has been shown to interact with mitochondrial electron transport chain components, influence redox-sensitive enzymes, and modulate intracellular reactive oxygen and nitrogen species generation. These biochemical properties make it a frequently used tool in studies of mitochondrial efficiency, oxidative stress modeling, and cellular energy metabolism.

In laboratory research environments, methylene blue has been utilized across a range of experimental platforms including cell culture systems, isolated mitochondrial preparations, and animal models designed to examine bioenergetic and redox-related processes.

• Experimental modeling of mitochondrial electron transport dynamics
• Investigation of oxidative and nitrosative stress pathways
• Analysis of redox-sensitive signaling cascades
• Photodynamic research models involving light-activated redox reactions
• Use as a histological and cellular staining reagent

Mechanistic studies describe methylene blue as an alternative electron carrier capable of interacting with mitochondrial complexes I–IV. By serving as a redox shuttle, it has been observed to influence electron flow efficiency and reduce electron leakage that contributes to reactive oxygen species generation.

Additional experimental observations describe interactions with nitric oxide–related signaling, monoamine oxidase activity, and redox-sensitive apoptotic pathways. All mechanistic descriptions remain confined to biochemical and molecular observations in controlled research models.

Preclinical publications report observations of methylene blue in in-vitro systems and animal models examining mitochondrial efficiency, oxidative stress modulation, cellular survival markers, and photodynamic responses.

These studies describe correlations between redox modulation and cellular energy parameters without extending conclusions beyond experimental research conditions. No clinical or translational claims are implied.

Methylene blue is supplied as a research-grade chemical material. Identity and purity are typically characterized using spectroscopic, chromatographic, and mass-based analytical techniques appropriate for laboratory reagents.

1. M. Bužga et al., “Methylene blue: a controversial diagnostic acid and medication?,” Toxicol Res (Camb), vol. 11, no. 5, pp. 711–717, Aug. 2022, doi: 10.1093/toxres/tfac050.

2. S. Srivastava, “The Mitochondrial Basis of Aging and Age-Related Disorders,” Genes (Basel), vol. 8, no. 12, p. 398, Dec. 2017, doi: 10.3390/genes8120398.

3. D. Tucker, Y. Lu, and Q. Zhang, “From Mitochondrial Function to Neuroprotection – An Emerging Role for Methylene Blue,” Mol Neurobiol, vol. 55, no. 6, pp. 5137–5153, Jun. 2018, doi: 10.1007/s12035-017-0712-2.

4. A. P. Gureev, I. S. Sadovnikova, and V. N. Popov, “Molecular Mechanisms of the Neuroprotective Effect of Methylene Blue,” Biochemistry (Mosc), vol. 87, no. 9, pp. 940–956, Sep. 2022, doi: 10.1134/S0006297922090073.

5. T. Mori et al., “Methylene Blue Modulates β-Secretase, Reverses Cerebral Amyloidosis, and Improves Cognition in Transgenic Mice,” J Biol Chem, vol. 289, no. 44, pp. 30303–30317, Oct. 2014, doi: 10.1074/jbc.M114.568212.

6. Y. Liu et al., “Customized Intranasal Hydrogel Delivering Methylene Blue Ameliorates Cognitive Dysfunction against Alzheimer’s Disease,” Adv Mater, vol. 36, no. 19, p. e2307081, May 2024, doi: 10.1002/adma.202307081.

7. M. Aimir, A. Nasser, J. Rokayah, M. Hardin, and M. Sohail, “The sensitivity and specificity of methylene blue dye as a single agent in sentinel lymph node biopsy for early breast cancer,” Med J Malaysia, vol. 77, no. 5, pp. 552–557, Sep. 2022.

8. A. F. dos Santos et al., “Methylene blue photodynamic therapy induces selective and massive cell death in human breast cancer cells,” BMC Cancer, vol. 17, p. 194, Mar. 2017, doi: 10.1186/s12885-017-3179-7.

9. R. F. Turchiello, C. S. Oliveira, A. U. Fernandes, S. L. Gómez, and M. S. Baptista, “Methylene blue-mediated Photodynamic Therapy in human retinoblastoma cell lines,” J Photochem Photobiol B, vol. 222, p. 112260, Sep. 2021, doi: 10.1016/j.jphotobiol.2021.112260.

10. H. Xue, A. Thaivalappil, and K. Cao, “The Potentials of Methylene Blue as an Anti-Aging Drug,” Cells, vol. 10, no. 12, p. 3379, Dec. 2021, doi: 10.3390/cells10123379.

11. M. E. Bauer and A. L. Teixeira, “Inflammation in psychiatric disorders: what comes first?,” Ann N Y Acad Sci, vol. 1437, no. 1, pp. 57–67, Feb. 2019, doi: 10.1111/nyas.13712.

12. M. J. Gandal et al., “GABAB-mediated rescue of altered excitatory-inhibitory balance, gamma synchrony and behavioral deficits following constitutive NMDAR-hypofunction,” Transl Psychiatry, vol. 2, no. 7, p. e142, Jul. 2012, doi: 10.1038/tp.2012.69.

13. M. Alda et al., “Methylene blue treatment for residual symptoms of bipolar disorder: randomised crossover study,” Br J Psychiatry, vol. 210, no. 1, pp. 54–60, Jan. 2017, doi: 10.1192/bjp.bp.115.173930.

14. M. Alda, “Methylene Blue in the Treatment of Neuropsychiatric Disorders,” CNS Drugs, vol. 33, no. 8, pp. 719–725, Aug. 2019, doi: 10.1007/s40263-019-00641-3.
15. L. Zhou, J. Flores, A. Noël, O. Beauchet, P. J. Sjöström, and A. C. LeBlanc, “Methylene blue inhibits Caspase-6 activity, and reverses Caspase-6-induced cognitive impairment and neuroinflammation in aged mice,” Acta Neuropathol Commun, vol. 7, p. 210, Dec. 2019, doi: 10.1186/s40478-019-0856-6.

ALL ARTICLES AND PRODUCT INFORMATION PROVIDED ON THIS WEBSITE ARE FOR INFORMATIONAL AND EDUCATIONAL PURPOSES ONLY.

The products offered on this website are furnished for in-vitro studies only. In-vitro studies (Latin: in glass) are performed outside of the body. These products are not medicines or drugs and have not been approved by the FDA to prevent, treat or cure any medical condition, ailment or disease. Bodily introduction of any kind into humans or animals is strictly forbidden by law.

For Laboratory Research Only. Not for human use, medical use, diagnostic use, or veterinary use.