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Invitrogen™ DiR'; DiIC18(7) (1,1'-Dioctadecyl-3,3,3',3'-Tetramethylindotricarbocyanine Iodide)
Description
The near IR fluorescent, lipophilic carbocyanine DiOC18(7) ('DiR') is weakly fluorescent in water but highly fluorescent and quite photostable when incorporated into membranes. The sulfonate groups incorporated into this DiI analog improves water solubility. It has an extremely high extinction coefficient and short excited-state lifetimes (∼1 nanosecond) in lipid environments. Once applied to cells, the dye diffuses laterally within the plasma membrane.
Prepare stock solutions of lipophilic tracers in dimethyl formamide (DMF), dimethylsulfoxide (DMSO), or ethanol at 1 to 2.5 mg/mL.
Order Info
Shipping Condition: Room Temperature
Specifications
Specifications
| Color | Infrared |
| Content And Storage | Store at room temperature and protect from light. |
| For Use With (Equipment) | Fluorescence Microscope |
| Quantity | 10 mg |
| Detection Method | Fluorescence |
| Shipping Condition | Room Temperature |
| Product Type | Liphophilic Tracer |
| Sub Cellular Localization | Cell Membranes, Lipids, Plasma Membrane |
Frequently Asked Questions (FAQs)
Lipophilic cyanine dyes, such as DiI (Cat. No. D282), DiO (Cat. No. D275), DiD (Cat. No. D7757) or DiR (Cat. No. D12731), are commonly used. The longer the alkyl chain on the dye, the better the retention in lipophilic environments.
If the tracer you chose is a lipophilic dye and fix with methanol, the lipids are lost with the methanol. If you have to use methanol fixation then choose a tracer that will covalently bind to proteins in the neurons.
Since these dyes insert into lipid membranes, any disruption of the membranes leads to loss of the dye. This includes permeabilization with detergents like Triton X-100 or organic solvents like methanol. Permeabilization is necessary for intracellular antibody labeling, leading to loss of the dye. Instead, a reactive dye such as CFDA SE should be used to allow for covalent attachment to cellular components, thus providing for better retention upon fixation and permeabilization.
DiI is a lipophilic dye that resides mostly in lipids in the cell, when cells are permeabilized with detergent or fixed using alcohol this strips away the lipid and the dye. If permeabilization is required CM-DiI can be used because this binds covalently to proteins in the membrane; some signal is lost upon fixation/permeabilization, but enough signal should be retained to make detection possible.
The transport is fairly slow, around 6 mm/day in live tissue and slower in fixed tissue, so diffusion of lipophilic carbocyanine tracers from the point of their application to the terminus of a neuron can take several days to weeks The FAST DiO and DiI analogs (which have unsaturated alkyl tails) can improve transport rate by around 50%.
For Research Use Only. Not for use in diagnostic procedures.