CellTracker™ CM-DiI Dye, 20 x 50μg - FAQs

View additional product information for CellTracker™ CM-DiI Dye - FAQs (C7001, C7000)

10 product FAQs found

I want to do a cell migration study for around 4 hours and need to fluorescently label the cells with a dye. What do you recommend?

Calcein, AM and FDA (fluorescein diaceate) are examples of some dyes used for this application. Since these dyes are not incorporated or covalently attached to any cellular components, they may have a short retention time as some cell types may actively efflux the dye out of the cells. The CellTracker and CellTrace dyes include either a mild thiol-reactive chloromethyl group or amine-reactive succinnimidyl ester group to allow for covalent binding to cellular components, providing for better retention. As with any reagent, one should empirically determine retention times for the cell type used.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I want to perform a cell fusion assay, where one cell line is labeled with one color and the other cell line with another color, and combine with a nucleic acid stain. What do you recommend?

A typical method is to label one cell line with orange fluorescent DiI C18 and the other cell line with green fluorescent DiO C18. These orange and green lipophilic cyanine dyes will stain the membranes of cells. Cells that fuse will then have both dyes, yielding a yellow color (when images are overlaid or cells are imaged in a dual-bandpass filter). These live cells can then be labeled with Hoechst 33342 (a cell-permeant blue DNA stain comparable in wavelength to DAPI), but only as an endpoint just before imaging (since DNA stains can interrupt DNA function).

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I need to look at live cell morphology deformation over the course of a few hours. What sort of membrane dye would be useful for this?

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.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I labeled my cells with Calcein, AM, but when I imaged the next day, there was no fluorescence from Calcein. Why?

Calcein, AM is a good choice for cell tracking and as a general cytoplasmic stain. However, it doesn't bind to anything and may be actively pumped out of the cells within a couple hours, which is likely what happened. The retention of Calcein within live cells is dependent upon the inherent properties of the cell type and culture conditions.

For long-term imaging, you may wish to consider a reactive cytoplasmic stains such as CFDA, SE or the CellTracker and CellTrace dyes.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

How do I prepare a stock solution of CellTracker CM-DiI Dye (Cat. No. C7000, C7001)?

A stock solution of CellTracker CM-DiI Dye (Cat. No. C7000, C7001) may be prepared in dimethyl formamide (DMF), dimethylsulfoxide (DMSO), or ethanol at a concentration of 1-2 mg/mL.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I stained two populations of cells, one with CellTracker Green and the other with CellTracker Red, but it looks like there may be crossover of the red dye to the green cells. What is going on?

One possibility is that there is spectral bleedthrough between the dyes. Be sure to check the single-color samples by imaging the red cells in green and imaging the green cells in red, using the optimal imaging settings for the other color. If you see bleedthrough with these controls, then you will have to reduce the dye label concentration to reduce the brightness of the dyes, or choose dyes that are farther apart spectrally. If the issue isn’t bleedthrough, another possibility is that the cells were not adequately washed after staining, allowing some unincorporated dye to remain and label the other cells after they were introduced. Extending washes and wash times should help with this.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I'm trying to stain my cells with CellTracker dyes or CFDA SE, but I'm not seeing much signal. What can I do?

First, make sure you aren’t staining in the presence of serum, since serum can have esterase activity that can prematurely cleave the AM group on these dyes, preventing entry into cells. After staining, it’s okay to return the cells to medium containing serum. After this, you can try increasing the concentration and label time to get a higher intensity.

Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.

I like how calcein dyes label the whole cell. How long can I track my cells with them, and can I fix them?

Calcein dyes diffuse into cells, the 'AM' moiety is cleaved by cellular esterases and then are observed in the cytoplasm without binding to anything. This provides a 'whole cell' label. Calcein dyes may be pumped out by normal cellular efflux mechanisms, sometimes within a very short time, especially for cell types that may exhibit drug resistance, unless the efflux is inhibited (such as with probenecid). The dyes are not crosslinked with aldehyde-based fixation, unlike protein-binding CellTracker dyes, and thus will be lost upon fixation. Additionally, any disruption of plasma membrane, such as with detergents or trypsinization, will lead to leakage of the dyes from the cell.

Find additional tips, troubleshooting help, and resources within our Cell Tracing and Tracking Support Center.

I want to track my cells with a nucleic acid stain, like DAPI or Hoechst dye. Do you recommend this?

This is not recommended. When these stains bind to DNA and RNA, they may affect the normal function of the nucleic acids, disrupting transcription, as well as replication. Other reagents, such as CellTracker dyes or Qtracker reagents are more optimized for tracking without disrupting normal activity. If a nuclear label is still desired, though, and the cells are mammalian and non-hematopoietic, CellLight nuclear reagents can transiently transfect cells to express GFP or RFP on a nuclear-expressing protein for up to several days without affecting function.

Find additional tips, troubleshooting help, and resources within our Cell Tracing and Tracking Support Center.

I want to track my cells over time, and you have a lot of options to choose from. How do I pick the right one?

Please see this Web link (http://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/cell-tracking.html) to help you choose the right option for your application. Start by planning how long you want to track your cells, then consider the mechanism of binding. Calcein dyes are very uniform in label and are good for short-term cell migration, but may be rapidly effluxed from some cell types. Lipophilic cyanine dyes, such as DiI, DiO, and similar dyes label cell membranes, don’t disrupt function, and can last longer, but have the potential to cross to other cells if membranes fuse. They are also lost upon permeabilization. CellTracker dyes are better for longer-term labeling, as they possess a mildly reactive chloromethyl moiety that allows covalent binding to cellular components. CFDA SE also covalently binds to cellular components. With all the reagents, their retention within cells is dependent upon the rate of cell division and the inherent properties of the cell (active efflux, membrane and protein turnover rates, etc.) and reagents that allow for covalent attachment exhibit longer retention than those that do not.

The longest-lasting and brightest options are the Qtracker reagents, which are taken up through endocytosis. These are so bright individual quantum dots can be detected, and are also robust enough to survive not only fixation and permeabilization, but even the heat and solvents used in paraffin processing.

Find additional tips, troubleshooting help, and resources within our Cell Tracing and Tracking Support Center.