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We narrowed to 813 results for: cell

Showing: 301 - 330 of 813 results
  1. A Practical Approach to Choosing the B(right)est Fluorescent Protein

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    Blog Post
    ...dodge cellular variation observed in mammalian cells is to tag an endogenous gene. By imaging cells (or ...mammalian cells within the dish. This is caused by the stochastic nature of plasmid uptake by cells. To correct...intended application. The three key properties for live cell imaging that will be treated in this series of posts...Determining practical brightness When a dish of mammalian cells is transiently transfected with a plasmid containing...allows for a precise determination of brightness in cells, under realistic experimental conditions. By determining...al (2017) and Heppert et al (2016). In mammalian cells this would be possible with CRISPR/Cas-based genome...efficiency of the fluorescent protein in the host cell, which is a key determinant of the practical brightness...
  2. Top Requested Lentivirus and AAV of 2016

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    Blog Post
    ...expressed in cells that express cre recombinase. Typically, this feature is used to attain cell-specific ...CRISPR applications and can be expressed from your cell line of choice after transduction with this virus...blast virus can be used to generate Cas9-expressing cell lines, which can then be used both for screens (...viral prep to create a single stable Cas9-expressing cell line and then transduce this line with lentiviruses...using lentiCas9-blast to generate Cas9-expressing cells. To ensure that this growth rate effect doesn’t ...activating particular signaling pathways in specific cell types (typically neurons). While all of these viruses...transduction and transgene expression across different cell types (Aschauer et al., 2013). Expression of hM4D...
  3. Tetbow: Bright Multicolor Labeling for Neuronal Tracing

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    ...imaging with single-cell resolution using chemical cocktails and computational analysis." Cell 157.3 (2014):... of the XFP genes is introduced at ~2 copies per cell per color, following a Poisson distribution. To ... optimal expression of XFPs. Any longer and the cells may start to show morphological abnormalities due...XFP genes have to be introduced at ~2 copies per cell per color to achieve the highest color variations... wait too long, as too much XFP is toxic to the cells. Inadequate expression levels of XFPs - Reduce the...video below depicting dendrite wiring of mitral cells.   Many thanks to our guest bloggers Richi Sakaguchi...circuitry with an index-optimized clearing agent." Cell reports14.11 (2016): 2718-2732. PubMed PMID: 26972009...
  4. The Open Repository of CRISPR Screens: CRISPR Screen Data in One Place

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    Blog Post
    ... disease, cell type or drug treatment can browse through screens performed in relevant cell lines or conditions... currently houses over 890 CRISPR screens in 629 cell lines, each manually curated and annotated from ...feasibility and power of CRISPR-based library screens in cell lines from humans and other species. By accurately... screens performed in 26 different breast cancer cell lines. Screenshot updated 2024. Each screen ...screen is captured by BioGRID curators, including the cell line/tissue type, enzyme system, sgRNA library and...example phenotype screens with read-outs other than cell viability. The following video provides an in-depth...
  5. Fluorescent Proteins 101: Fluorescent Biosensors

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    Blog Post
    ...Localization within cells Fluorescence microscopy Visualize components of individual cells Separation/identification...fluorescently-labeled components Fluorescence-activated cell sorting (for cells); fluorescent HPLC (proteins or other molecules...biosensor Before expressing a biosensor in eukaryotic cells, think about the best place for the biosensor to...average amount of fluorescence across a population of cells (i.e. in a plate well). Use to track a process (... molecules) Isolate or quantify cells, proteins or other molecules that have been labelled with your fluorescent...be expressed. Are you looking at an intracellular or extracellular molecule? By fusing a biosensor to ...by Olivier Pertz’s lab. Other biosensors track cellular characteristics like pH, redox state, and voltage...
  6. Cre-ating New Methods for Site-specific Recombination in Drosophila

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    Blog Post
    ...recombination varies for different constructs and cell types. Second, Cre may induce recombination at pseudo...standard UAS/GAL4 system is toxic to proliferating cells. A Cre-estrogen receptor ligand binding domain-fusion...recombination efficiency. When expressed in neuronal cells, each line showed broad recombinase-dependent RFP...these recombinases were also active in mammalian cells. In experiments, B3 and KD were shown to be functional...functional in cultured Chinese hamster ovary (CHO) cells, as well as in cortical neurons in layer 2/3 of ... damage induced by Cre recombinase in mammalian cells. Loonstra A, Voojis M, Beverloo HB, Al Allak B, ...recombinase toxicity in proliferating Drosophila cells by estrogen-dependent activity regulation. Heidmann...
  7. In Living Color: The Skinny on In Vivo Imaging Tools

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    ...eight millimeters – not single cells (yet) but small clusters of cells. Looking ahead What’s next, you...fluorescent proteins to observe what’s happening inside cells for at least a couple of decades. Green is the classic...and tracking of proteins, organelles, and living cells in a spatiotemporal manner, which is not possible... vivo. “One of the reasons we can’t localize one cell at a depth of one centimeter with fluorescence is...on the other hand, are larger than the size of a cell, so they scatter much less. As a result, ultrasound...brighter, more photostable, smaller, and less toxic to cells. They’d like to make near-infrared fluorescent proteins...
  8. Plasmid Preps: Different Purity, Different Quantities, Different Uses

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    Blog Post
    ...lipopolysaccharide of the cell wall of Gram negative bacteria like E. coli that affects tissue culture cell line viability...introduces transformation grade plasmids into a bacterial cell. Transformation grade DNA  Transformation is ...transformation of chemically and electrocompetent cells is minimal (picogram range). It can be extracted...Figure 3: Need to introduce plasmids into mammalian cells? Use transfection grade DNA. Transfection is ...process of inserting an external plasmid in mammalian cells and it will likely require micrograms of plasmid...
  9. Chromoproteins: Colorful Proteins For Molecular Biology Experiments

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    Blog Post
    ... them into your cells, you can simply look for blue colonies to determine which cells have taken up the... mScarlet as the donor in HeLa cells.   Find ShadowR for mammalian cell expression here   Now that you... that the cellular fitness cost varied greatly between chromoproteins. In some cases, cells containing...cloning experiment worked just by looking at the cells on the plate. For example, if your plasmid contains...Here, the chromoprotein is expressed and gives the cell a magenta (amilCP) or purple (tsPurple) color. Though...added which induces expression of the toxin. Any cells that grow after this point will be those that have...resonance energy transfer (FLIM-FRET) in living cells (Figure 4). They created ShadowR by modifying the...
  10. Uncovering Ancestral Bias in CRISPR Research

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    Blog Post
    ...ancestry and germline sequence variation in cancer cell lines took them down unexpected paths. Though this...researchers do large-scale CRISPR screens in cancer cell lines, looking to uncover genetic dependencies of...to see if they could identify the ancestry of the cell lines (European, East Asian, Indigenous American...or South Asian) used in the screens based on the cells’ germline genetic variations. They then wanted to...with each ancestry group. Since about 90% of the cell lines used in DepMap CRISPR screens are of either...groups for 994 of the Cancer Dependency Map cancer cell lines (left). Heatmap indicating the breakdown of...CRISPR guides, short pieces of RNA that bind to a cell’s DNA, telling the Cas machinery where to cut.  ...
  11. Fluorescent Tagging of Endogenous Genes with SapTrap

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    ...Depletion in Human Cells by Auxin-Inducible Degron Tagging with Short Homology Donors.” Cell Rep.15(1) (2016...and function of cellular systems. FPs have been used to track protein localization, cell structure, intracellular...to fluorescently tag markers of cellular structures in mammalian cells. These plasmids use fluorescent...loci in other model systems, including mammalian cells. CRISPaint (CRISPR-assisted insertion tagging)...C-terminal tag fusions of endogenous genes in human cells. To use CRISPaint, users need 3 vectors:  1) a gRNA...also be introduced directly into a Drosophila S2 cell line stably expressing Cas9. This PCR toolkit offers...selection. Researchers at the Allen Institute for Cell Science recently developed a collection of plasmids...
  12. What's New in CRISPR - November 2021

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    ... into AAV particles for delivery into mammalian cells, especially when fused to effector proteins for ..., base editing, and genome editing in mammalian cells. The “V4” version (named CasMINI) had the highest...an active nuclease.  Read the paper in Molecular Cell Find the CasMINI plasmids Efficient CRISPR editing...effective in genome editing in both bacteria and human cells using various delivery methods, including plasmid...mRNA or Cas9 mRNA and sgRNA, in human and mouse cells. They further develop a version of SEND for gene...modular system for delivering gene editing tools into cells. Image adapted from Segel et al. 2021.   Prime...correct mutations in a variety of target genes and cell types. Their Nature Biotechnology paper showcases...
  13. Lighting Up Cell Signaling with Photoswitchable Kinases

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    ...of Multiple Kinase Activities in Live Single Cells." Cell 157, no. 7 (2014): 1724-734. PubMed PMID: 24949979...Signal transduction pathways are a lot like cell phone networks. Protein kinases deliver messages to ... dimeric Dronpa is less prone to aggregation in cells compared to the tetrameric Dronpa it was derived...inhibitors, psMEK1 and ERK KTR-mRuby2 expressing cells were incubated with an inhibitor of choice, exposed...inactivation, and then decreases. Treatment of the cells with a PP1/PP2A inhibitor leads to maintenance of...Raf-MEK-ERK signaling in the hypodermis and gut cells of C. elegans causes the same phenotype. Activation...signaling pathway with psRaf1 or psMEK1 in these same cells by 24-48 hours exposure to blue light also induced...
  14. Choosing the B(right)est Fluorescent Protein: Photostability

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    Blog Post
    ...intensity evolves over time in living cells at a power used for live-cell imaging. To conclude, the most photostable...molecule will photobleach at some point. For live-cell imaging, it is desirable to have fluorescent proteins...experiment. The best fluorescent proteins for live cell imaging can be excited many times, thereby producing...protein is a key requirement for quantitative live-cell imaging, it is important to be able to quantify ...it is advisable to perform time-lapse imaging of cells producing the fluorescent protein of interest under...natural situation. Measuring photostability in living cells provides a much more realistic view of photostability...spectral class on the microscopy system and in the cell type (or tissue) that is intended to be used with...
  15. Plasmids 101: CcdB - The Toxic Key to Efficient Cloning

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    ... protein (CcdA) that protects the cell against the toxic CcdB. Cells that lose ccdA through the loss of...disrupted allowing cells expressing the recombinant plasmid to propagate. Any cells that contained non-recombinant...which is responsible for plasmid maintenance during cell division. ccdB codes for the toxic protein (CcdB...broken double stranded DNA and ultimately causing cell death. ccdA, another gene found in the ccd operon...Gateway takes advantage of the same principle that cells will not propagate while expressing the gene. Briefly...can one work with a plasmid/gene that kills the cells expressing it? The answer lies in special strains...PMID: 8254658. 5. Bernard, P. and Couturier, M. “Cell killing by the F plasmid CcdB protein involves poisoning...
  16. Multiple Plasmids at a Low Price: Kits from Addgene

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    ...Purification Process with pCri Cell-free protein expression kit Cell-free expression systems have been...testing and comparison of different cell-free expression systems; the Cell-free expression test kit represents...SITS to create the pCell-Free vectors, Gateway-compatible backbones that enable cell-free expression of...: FX Cloning Kit BIOFAB Plasmid Set pCri System Cell Free Protein Expression Kit FREQ Seq PUF Assembly...facilitate gene expression in bacteria, yeast, mammalian cells, insects, and even Xenopus oocytes. The expression...of proteins in both prokaryotic and eukaryotic cell extracts (Gagoski et al 2015). He has also constructed...to perform statistically relevant benchmarking of cell-free expression systems, and tested for product ...
  17. Flow Cytometry Readouts: Yes, No, and Everything in Between

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    ...percentage of total live cells are GFP+. In this plot, with adjusted voltage, cells that did not receive ...would serve you well. Percentage of cells in a parent gate (all live cells for example) that are positive ...example, you have introduced a GFP protein into your cells (visualized via the FITC channel) and you are trying...graphs could simply be the percentage of the total cells present in the gate.   Figure 1: Example...looking at proteins that are expressed regularly in cells and might be upregulated or downregulated based ...populations. MFI is the average brightness from all cells that are positive for the marker of interest. MFI...
  18. Quick Guide to Working with Drosophila Part 2: Controlling Gene Expression in Flies with Gal4/UAS

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    ... to express one gene in one cell type and another gene in a different cell type (6–8). Although it’s often...systematically study gene function with temporal control and cell-type specificity! The Gal4/UAS system At a more...the hedgehog gene can be overexpressed in several cell types by using different Gal4 drivers. It is much...much easier to mate flies to get the right cell type expression as opposed to making a new fly with hedgehog... Targeted gene expression as a means of altering cell fates and generating dominant phenotypes., Development...Neuro-Trauma during Asymptomatic Viral Infections, Cell Host Microbe 22, 48-60 (2017). PubMed PMID: 28704652...expression, lineage tracing, and mosaic analysis., Cell 141, 536–48 (2010). PubMed PMID: 20434990. PubMed...
  19. Transferable Skills Guide: Time Management

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    ...splitting my cells first. Time management through planning I probably wouldn’t have fallen into my cell splitting...for Scientists. Back when I used to do mammalian cell culture, I would often respond to friends asking...there in a few minutes, I just need to split some cells.” Inevitably, this task would take longer than I...since my days as an undergrad working with cancer cell lines. As I started planning out my own experiments.... In my anecdote above, I prioritized splitting cells over meeting up with friends, but didn’t realize...mean in terms of the utility of your tasks. In my cell splitting anecdote, I probably could have grabbed...with friends and come back to the lab to split my cells later. Eating with friends has a somewhat immediate...
  20. Plasmids 101: Stringent Regulation of Replication

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    ...replicating too quickly can slow cell growth or even kill the host cell. For stringently controlled plasmids...All plasmids rely on their host cell's replication machinery in order to replicate—but not always to ...be synchronized with the replication of the host cell's chromosomal DNA.  Plasmids are said to be under... stringent control when they depend on the host cell’s initiation proteins to start their own replication... occurs at the appropriate time—for example, the cell must have enough nutrients available to complete...the amount of active DnaA available is one of a cell’s best tools to regulate DNA replication. DnaA negatively...energy source, ATP binding is one more way for the cell to control DNA replication. A variety of other proteins...
  21. A Tour of Addgene's Most Popular Pooled Libraries

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    ...single-cell level. CRISPR libraries CRISPR screening has become a popular tool for probing cellular pathways...barcodes allow researchers to identify specific cells — as well as their descendants. This makes them ... for lineage tracing, among other applications. Cells can be identified using fluorescence, like in the...barcoding approach to observe clonal dynamics and cell lineage. Variations of this library allow tracking...mutations that prevent their expression. The knockout cells can be used to identify genes that underlie a particular...genome-wide knockout screens in mouse and human cells, respectively. Last month, the David Root and John...proteins to be expressed on the surface of a host cell or virus, such as a yeast or bacteriophage species...
  22. New Optimized Genome-wide CRISPRko, CRISPRi, and CRISPRa Libraries

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    ...when trying to screen a limited number of cells like primary cells or in vivo. Recently, the labs of David... cultured cells as well as more difficult conditions such as model systems and primary cells. References...with both A375 (melanoma) and AT29 (colon cancer) cells and assessed the libraries performance via the depletion...important criterion for probing a limited number of cells. Get the Brunello CRISPRko sgRNA library as pooled...subject to an increase in dsDNA breaks that can cause cell death. Thus, CRISPR inhibition (CRISPRi) libraries...study screening for vemurafenib resistance in A375 cells. The SAM system (CRISPR/Cas9 Synergistic Activation...CRISPR-mediated control of gene repression and activation." Cell 159.3 (2014): 647-661. PubMed PMID: 25307932. PubMed...
  23. AAVs in Retinal Gene Therapy

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    ...expression in non-dividing cells because they remain in episomal form in the cell’s nucleus. But since nothing...hope are many more clinical successes for gene (and cell) therapies. One may wonder why the first AAV-based... providing long-term gene expression in retinal cells - AAV - were becoming available. At the same time... lentivirus (LV) are known to transduce retinal cells, AAV quickly became the vector of choice for ocular...long term expression in dividing and non-dividing cells due to its (random) integration into the genome,...limited tropism in the retina, primarily infecting cells of the retinal pigmented epithelium (RPE). AAVs... for patients, this gene can be targeted to RPE cells using a lentiviral vector and a clinical trial is...
  24. Plasmids 101: Multicistronic Vectors

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    ...them. Why Use multicistronic vectors? Detecting cells that are expressing your gene, especially if you...reporters allow you to easily screen or select for cells that are expressing your gene of interest at high...promoter, multicistronic plasmids ensure that any cells that are positive for your marker should also be...anytime you want to express multiple genes in the same cell. Although it is possible to drive co-expression ...promotes translation of the viral genome in eukaryotic cells.1,2 Since then, a variety of IRES sequences have... cistron due to factors such as the experimental cell type and the specific genes cloned into the vector...scientists. 2A cleavage is universal in eukaryotic cells, and, although some scientists report close to 100%...
  25. An Interview with Connie Cepko - Gene Therapy, Plasmid Tools and Insights to Success

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    ...fluorescent proteins as scaffolds for cell-specific gene manipulation.” Cell 154(4) (2013): 928-939. PubMed ...Cepko Interested in Working on the Eye 9:05-10:16 : Cell Targeting in Retinal Gene Therapies 10:17-14:34 ...28:39 : Methods for Delivering Multiple Genes to Cells for Gene Therapy 28:40-35:10 : GFP Activatable Tools...publication at Addgene. 2. Tang, Jonathan C.Y., et al. “Cell type-specific manipulation with GFP-dependent Cre...
  26. Antibodies 101: Conventional vs Spectral Flow Cytometry

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    ...co-expression among cellular markers You’ll also need to know if markers are co-expressed in your cells when designing...immunologists, allowing for the rapid analysis of cell populations within a heterogenous tissue type, such...methods, the identification and isolation of rare cell types. In recent years, full spectrum flow cytometry...Spectral flow allows for autofluorescence extraction Cells produce a low level of fluorescence called autofluorescence...single color control. Reference controls: Beads or cells? Compensation beads are a convenient tool to obtain...you prepare reference controls of both beads and cells for a single fluorophore. Although compensation ...Additionally, it is critical to include unstained beads or cells within your reference group to ensure proper unmixing...
  27. A new platform for fast functional characterization of potentially cancerous mutations

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    ... Ba/F3 and MCF10A cellular models. Ba/F3 and MCF10A are growth factor dependent cell lines and any mutations...attempting to characterize mutations in a pooled cell population, as mutations with strong phenotypic ...functional groups, based on how each one impacted cell viability (see figure). Most of the mutations were...to be “neutral,” having no significant effect on cell viability compared to a wild-type control. Approximately... the mutations, however, significantly increased cell viability, and these “activators” may be the direct...annotation of somatic mutations in cancer." Cancer Cell 33.3 (2018): 450-462. PubMed PMID: 29533785. PubMed...
  28. 22 Hot Plasmid Technologies from 2014

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    ...fluorescence images of C2C12 cells stably expressing pTRE-Tight-MitoTimer and rtTA. The cells were pulsed with 2µg... Robinson et al., Dev Cell 2010 Feb 16;18(2):324-31. Cheeseman et al., J Cell Sci 2013 May 1;126(Pt ...neighboring cells in imaging applications and the mapping of neuronal projections to their associated cell bodies... targeted to subcellular regions or protein complexes for proteomic mapping in live cells. Lam et al...been used by several groups to monitor protein and cell ageing, as the spectrum shift occurs during Timer...(pTRE-Tight-MitoTimer) to show its usefulness in cell culture to report changes in mitochondrial turnover...rapamycin-binding domains, such as FKBP and FRB. The cell does not appear to mind extraneous proteins bound...
  29. Brain Initiative Collection

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    Collection
    ...real-time interrogation and monitoring of brain cells and circuits during behavior. Long desired by researchers...A somatic channelrhodopsin, which enables single cell, single millisecond resolution optogenetics. Human...A somatic channelrhodopsin, which enables single cell, single millisecond resolution optogenetics. Cre-dependent...genetically encoded dopamine sensor RdLight1 in mammalian cells. Lin Tian 125708-AAV9 pAAV-hSynapsin1-RdLight1 Expresses...neurons Yulong Li 158757-AAV8 pAAV-CAG-SomaGCaMP6f2 Cell body-targeted GCaMP6f, under CAG promoter: GCaMP6f... Edward Boyden 158757-AAV9 pAAV-CAG-SomaGCaMP6f2 Cell body-targeted GCaMP6f, under CAG promoter: GCaMP6f...
  30. Plasmids 101: Screening Strategies Used in Plasmid Cloning

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    ...activity. These cells, presumably the cell you want, cannot break down X-gal and are white. Cells that don’t...killing off a portion of the cells like in a selection. Instead, all cells survive and you will need to... the plasmid you’re looking for out of the many cells that don’t. One way to begin the search is by using...using selection strategies, where only cells that have gained or lost a specific gene survive (ex: antibiotic... plates containing X-gal allows you to identify cells that took up the vector and distinguish between ...
Showing: 301 - 330 of 813 results