DilC12(3) (iodide)
[CAS# 75664-01-6]

Identification

• Classification: Organic raw materials >> Heterocyclic compound >> Indoles
• Name: DilC12(3) (iodide)
• Synonyms: 1-Dodecyl-2-[3-(1-dodecyl-3,3-dimethylindol-1-ium-2-yl)prop-2-enylidene]-3,3-dimethylindole;perchlorate
• Molecular Formula: C₄₇H₇₃ClN₂O₄
• Molecular Weight: 765.55
• CAS Registry Number: 75664-01-6
• EC Number: 887-558-6
• SMILES: CCCCCCCCCCCCN1C2=CC=CC=C2C(C1=CC=CC3=[N+](C4=CC=CC=C4C3(C)C)CCCCCCCCCCCC)(C)C.[O-]Cl(=O)(=O)=O

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H315-H319
• Precautionary Statements: P264-P280-P302+P352-P337+P313-P305+P351+P338-P362+P364-P332+P313

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovory and Applicatios

DilC12(3) (iodide) is a **cationic lipophilic dye** commonly used in biological research for studying **membrane dynamics and labeling**. Chemically, it belongs to the class of **dialkylcarbocyanine dyes**, characterized by a polymethine chain connecting two nitrogen-containing heterocycles, with long alkyl chains attached to the nitrogen atoms. The "(3)" in DilC12(3) denotes the number of methylene units in the polymethine bridge or refers to the specific variant in the DilC12 series, while the iodide indicates that it is present as the counterion for the cationic dye.

The lipophilic nature of DilC12(3) allows it to **intercalate into lipid bilayers**, making it a useful fluorescent marker for **cell membranes, liposomes, and other lipid structures**. Upon incorporation into membranes, the dye exhibits **strong fluorescence** with emission and excitation properties that are compatible with standard fluorescence microscopy and flow cytometry setups. Its long alkyl chains enable stable incorporation into membranes without rapid diffusion out, providing consistent labeling for imaging studies.

DilC12(3) is widely used in research to investigate **membrane fusion, trafficking, and dynamics**. In studies of vesicle or liposome fusion, for example, the dye can be used to monitor lipid mixing by observing changes in fluorescence intensity due to self-quenching at high local concentrations. In cell biology, DilC12(3) can label live or fixed cells to visualize membrane structures, track organelle movement, or study cell-cell interactions. Its cationic nature also facilitates interactions with negatively charged lipid headgroups, enhancing membrane association.

From a chemical standpoint, the iodide counterion stabilizes the positively charged dye but does not significantly affect its membrane-labeling properties. Alternative counterions (such as chloride) are sometimes used depending on solubility requirements or experimental conditions. DilC12(3) is typically supplied as a solid or as a solution in organic solvents and must be handled with care to avoid photobleaching, as prolonged exposure to light can diminish fluorescence intensity.

Overall, DilC12(3) (iodide) is a versatile fluorescent dye for biological membranes, combining strong lipophilicity, stable fluorescence, and cationic character. Its utility in labeling lipid bilayers, tracking membrane dynamics, and monitoring fusion events makes it a standard tool in cell biology, biophysics, and membrane research.

References

2017. DiI Perfusion as a Method for Vascular Visualization in Ambystoma mexicanum. Journal of Visualized Experiments, 127.
DOI: 10.3791/55740

2016. Gustatory and general visceral centers and their connections in the brain of adult zebrafish: a carbocyanine dye tract-tracing study. Journal of Comparative Neurology, 524(12).
DOI: 10.1002/cne.24068