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View additional product information for CellTracker™ Fluorescent Probes - FAQs (C12881, C2102, C10094, C2111, C34552, C2110, C7025, C34551, C2927, C2925, C34565)
16 product FAQs found
一种可能性是染料之间的光谱渗漏。务必通过在绿光下成像红色细胞，在红光下成像绿色细胞的方式检查单色样品，对其他颜色使用最佳成像设置。如果您在对照中看到这些渗漏，那么就需要减少染料标记浓度以降低染料的亮度，或者选择那些光谱相距较远的染料。如果不是渗漏的问题，另一种可能性是细胞在染色后没有充分清洗，使得一些未结合的染料残留下来，这些染料进入后会标记其他细胞。延长清洗次数和时间应该会有帮助。
首先，确定您是在无血清条件下进行染色的。因为血清具有酯酶活性，会过早的裂解这些染料上的AM基团，进而阻止其进入细胞。染色之后即可将细胞移回含血清培养基中。除此之外，您可以尝试增加浓度和标记时间以获得更高的强度的信号。
钙黄绿素染料扩散到细胞中，“AM”部分由细胞酯酶切割，随后可以在细胞质中观察到而未结合任何胞内成分。这意味着它们标记了“整个细胞”。但是这也意味着它们可以通过正常细胞的外排机制被泵出。有时这一过程时间很短，尤其是显示出抗药性类型的细胞，除非外排被抑制（如使用丙磺舒抑制外排）。这也意味着染料不能被醛类固定剂所交联（不同于蛋白质结合CellTracker染料），因此染料会在固定时丢失。此外，质膜的任何干扰（例如去垢剂或胰蛋白酶处理）都会导致染料从细胞中渗漏。
这是不推荐的。这些染料与DNA和RNA的结合会影响核酸的正常功能，扰乱转录和增殖。诸如CellTracker染料或Qtracker试剂在不严重扰乱细胞正常活动的条件下对其进行追踪。如果您仍需要使用核酸染料进行标记且细胞是哺乳动物和非血液来源的话，CellLight 细胞核试剂可通过瞬时转染进入细胞，在核表达蛋白上表达GFP或RFP长达数天而不影响其功能。
请浏览这里（https://www.thermofisher.com/us/en/home/life-science/cell-analysis/cell-tracing-tracking-and-morphology/cell-tracking.html）以帮助您选择适合您的应用的产品。首先确定追踪细胞的时间，然后考虑染料结合机制。钙黄绿素染料标记均匀且对短期细胞迁移示踪效果极佳，但也会被某些类型细胞迅速外排。亲脂性的花青素染料，如DiI，DIO，和类似的染料能标记细胞膜而不破坏其功能，并且能持续更长时间，但如果发生膜融合则可能会染上其他细胞。此外，它们还会在透化过程中丢失。CellTracker染料更有利于长期标记，其带有温和的氯甲基反应基团使之能够与细胞组分共价结合。CFDA SE也能共价地结合于细胞组分。在所有列出的试剂中，细胞内保留与否取决于细胞分裂的速率和细胞的固有特性（主动外排，膜和蛋白质的周转率等）。其中共价结合试剂比非共价结合的试剂展现出更长的保留时间。
Qtracker试剂是最持久并且荧光强度最高的细胞示踪染料，它通过内吞作用被细胞摄入。在许多样品中它们产生的信号可以持续检测长达数周，而且信号足够强，即使在固定和通透甚至加热和石蜡处理过程中，仍然能够维持较好的荧光信号。
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.
DAPI is considered a semi-permeant/impermeant nucleic acid stain. Staining of nucleic is dependent upon the cell line in its performance. Some cell lines will label with DAPI, others not at all, and others label inconsistenly. Instead, we recommend using either Hoechst 33342 or Hoechst 33258, which have the same wavelength and binding mode as DAPI (at the A-T minor groove) but are readily cell-permeant.
Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.
We do not recommend doing this. DAPI is considered to be a semi-permeant/impermeant nucleic acid stain. DAPI staining of live cells may be inconsistent. It is best used as a counterstain for fixed samples. Other cell permeable nucleic acid stains, such as Hoechst or the SYTO dyes may affect cellular function.
For mammalian cells, we recommend using the CellLight Nucleus transduction reagents, available in CFP, GFP and RFP. With these reagents, the cells are transduced overnight in a single labeling step and the next day the nuclei will fluoresce. The label may be retained for 3-5 days and should not affect cell function. Cytoplasmic cell tracking dyes such as the CellTracker dyes may also be used.
Find additional tips, troubleshooting help, and resources within our Cell Analysis Support Center.
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.
Yes, the CellTracker dyes react with any accessible thiol part of the protein and can be fixed. However, some CellTracker dyes may be attached to small metabolites that can leak from the cell following permeabilization. This can result in decreased fluorescence.
Find additional tips, troubleshooting help, and resources within our Cell Tracing and Tracking Support Center.
The shelf life for CellTracker Green CMFDA Dye is one year after receiving it, when stored desiccated at -20 degrees C.
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.
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.
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.
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.
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.