We narrowed to 587 results for: cel.2;
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TypeBlog Post...containing complementary polynucleotide chains. J Virol 9(2): 394-396. Lecomte E, Tournaire B, Cogné B, Dupont... small amount of spurious DNA from the packaging cell line, helper and packaging plasmids. We decided ...
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Viral Vectors 101: Viruses as Biological Tools
TypeBlog Post...PubMed PMID: 8491198. PubMed Central PMCID: PMC413431. 2. Bukrinsky MI, et al. “Active nuclear import of human...Non-Dividing Cells Transient Gene Expression Low Tropism for Mouse Cells and Hematopoietic Cells Low Packaging...fuses with the target cell’s membrane, allowing the viral particle access into the cell. The viral envelope... of cell the virus will target and fuse with. In nature, this determines which organisms and cells they...viruses can be engineered to be cell type specific. Once inside the host cell, the virus unleashes its cargo...wide range of cell types that are typically ‘difficult to transfect’, such as primary cells. They can also... them to easily deliver their “cargo” to target cells and organisms, and when that cargo is designed to... -
All in a Twist: dsRNA
TypeBlog Post... would release them into the cytosol. Fig. 2: Endogenous sources of duplexed RNA DNA:RNA hybrids...mammalian cells. Here, we will cover how these structures are generated, why it’s important for cells to sense...., Hur, S. Cellular origins of dsRNA, their recognition and consequences. Nat Rev Mol Cell Biol, 23: 286...performs almost all of its biological functions in our cells in the single strand form, but double stranded RNA...with bidirectional transcription. In an uninfected cell, dsRNA rarely circulates, but upon viral infection... Fig. 1: Exogenous sources of dsRNA Cellular sources of dsRNA Transposable elements such as...While these molecules are clearly associated with cellular damage and dysfunction, it is unclear what the... -
Viral Vectors 101: Types of viruses
TypeBlog Post...Gene and Cell-Based Therapies in the New Era of Personalized Medicine. Genes Dis. 2017 Jun;4(2):43-63. ...dividing cells only, so is not suitable for infection of quiescent cells or infrequently cycling cells but ...non-dividing cells, making it conducive to targeting all cell types. Altogether, AAV has many excellent features...DNA copies of their genome upon infecting a host cell. This viral DNA (also called proviral DNA) is then...and permanently integrate a genetic cargo into a cell. These viruses have a cargo capacity of ~ 8 kb, ...needs, and can transduce (infect) a wide range of cell types with a high efficiency. However, gamma-retrovirus...but is fine for experiments with immortalized cell line cultures. Lentivirus Lentivirus is a type of retrovirus... -
Antibodies 101: Isotypes
TypeBlog Post... Figure 2: Isotype switching requires DNA recombination of the antibody gene locus. B cells start by ...the surface of basophils and mast cells, two types of white blood cells involved in allergic reactions. ... is important because it determines what immune cells and molecules are recruited by the antibody to help...each of these functions: Recruitment of immune cells that express receptors that recognize the Fc portion...which can initiate a cascade that helps attack extracellular pathogens. Transportation of antibodies to ...special receptors that transport antibodies through cells and into different body compartments, such as into... during a primary immune response because all B cells begin by expressing IgM. IgM has a pentamer structure... -
Viral Vectors 101: Viral Applications
TypeBlog Post... vaccines, including 1) cellular responses in addition to antibody response 2) very high immunogenicity...difficult-to-transfect cell types ranging from primary to embryonic stem cells. Viral integration of a... also generally less toxic to cells than transfections, preserving cell viability. Library delivery Screening...Viral applications Viruses work by infecting a host cell (the target of viral infection) and delivering a...to be anything you want delivered to your target cells. This delivered DNA/RNA can then be either permanently...permanently integrated into the genome of the target cell or transiently expressed. It’s important to note...This vector can express your construct in target cells transiently or constitutively depending on the virus... -
Hot Plasmids - May 2022
TypeBlog Post... those that also infect the liver. Fig. 2: Summary of the generational evolution of the AAV .... Nat Cell Biol. 2022. https://doi.org/10.1038/s41556-021-00836-1 Visual barcodes for live cell clonal...with one visual barcode per cell and up to 200-plex with two barcodes per cell. The researchers validated...long sequence knock-ins Visual barcodes for live cell clonal multiplexing Improving flexibility for ... powerful approach for proteomic mapping in both cell culture and whole organisms (see our 2019 overview...reduced risks of unwanted mutations in mammalian cells. Long sequences traditionally have higher risks ...multiplexing by: Rachel Leeson Multiplexed images in live cells remains a challenge due to multiple factors, including... -
Plasmids 101: Yeast Vectors
TypeBlog Post... the 2 micron circle (a natural yeast plasmid) allows for 50+ copies to stably propagate per cell. The...within an E. coli cell, but vectors can be widely utilized across many different cell types and each one... the yeast cell. These elements control not only the number of plasmids found in each cell, but also whether...are eukaryotes and thus contain complex internal cell structures similar to those of plants and animals...components to allow shuttling between E. coli and yeast cells. To be useful in the lab, the vectors must contain...replication (ORI) and a means of selection in yeast cells, in addition to the bacterial ORI and antibiotic...determines plasmid copy number within the bacterial cell. Similarly, the specific ORI elements included within... -
Communicating Your Science With Help From ComSciCon
TypeBlog Post...aspects of the work you presented may also be unclear. 2. Make the audience your primary focus When writing...as an opportunity to practice communicating. Excellent scientists learn from advisers and other mentors...help graduate students in all STEM fields become excellent science communicators. To empower graduate students... -
A Practical Approach to Choosing the B(right)est Fluorescent Protein
TypeBlog Post...closely mimicking the future application. In figure 2 we provide an example of the comparison of the practical...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... -
Hot Plasmids - February 2022
TypeBlog Post...acceptable variations in DR sequences. Figure 2: comparison of Cas 9 vs. Cas 12a expression cassettes... including live-cell imaging, single-molecule tracking, immunolabeling of fixed cells, Western blotting...possibilities in both cell engineering and gene therapy. Xiaoshu X, et al. Molecular Cell. 2021. https://doi.org...Anti-FLAG Frankenbodies for modular imaging of cellular targets Optimized genetic screening technique ...Anti-FLAG Frankenbodies for modular imaging of cellular targets by: Mike Lacy Adding to their set of anti-HA...well-folded scFv scaffold to improve its stability in cells, and use it in a variety of applications. This set...frankenbodies to amplify the signal. Liu et al. Genes Cells. 2021. https://doi.org/10.1111/gtc.12893, Zhao et... -
Hot Plasmids - March 2020 - base editors, GEVI, MoClo, and optogenetics
TypeBlog Post...higher quenching of mScarlet emission. Figure 2: Ace-mScarlet is a fusion between the voltage-sensitive...This novel tool is practical in cell and organ culture, as well as cell lineage studies. Eisenhoffer and...CreLite for cell tracing using the transgenic zebrafish model, ubi:zebrabow. In this system, cells express...fast-splicing split intein and co-infected into the cell. Intein splitting removes any exogenous sequences...split into two plasmids and co-transfected into cells for reconstitution. Image from Levy et al., 2020...red-light inducible optogenetic tool for precision in cell lineage tracing Article contributed by Erin Sanders...fluorescent proteins controlled by Cre recombination. Each cell can have multiple copies of the transgene that recombine... -
Protocol - pLKO.1 – TRC Cloning Vector
TypeProtocol...a. Plate target cells and incubate at 37°C, 5% CO 2 overnight. Day 2: b. Target cells should be approximately...plates and grow at 37°C, 5% CO 2 overnight. Day 2: b. The target cells should be approximately 80-90% ...materials D.2 Screening for inserts E. Producing Lentiviral Particles E.1 Recommended materials E.2 Protocol...Published articles H.2 Web resources I. Appendix I.1 Sequence of pLKO.1 TRC-Cloning Vector I.2 Recipes I.3 Warranty...VWR: #7177-48-2. Use at 100 μg/mL. Carbenicillin VWR: #80030-956. Use at 100 μg/mL. C.2 Annealing Oligos...oligo 5 μL Reverse oligo 5 μL 10x NEB buffer 2 35 μL ddH 2 O Incubate for 4 minutes at 95°C in a PCR machine...buffer 1 1 μL AgeI add ddH 2 O to bring to 50 μL final volume Incubate at 37°C for 2 hours. Purify with Qiaquick... -
Plasmids 101: Screening Strategies Used in Plasmid Cloning
TypeBlog Post...about colony PCR in this blog post. Figure 2: The steps of colony PCR. Sanger sequencing Sanger...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 ... -
Visualizing Protein Turnover In Situ
TypeBlog Post...PMID: 20543841. PubMed Central PMCID: PMC2920597. 2. Nathans, Daniel. "Puromycin inhibition of protein...proteins in cells. Homeostatic regulation of protein abundance is essential for normal cell function, and...one particular protein in neurons or in any other cell type. However, we cannot distinguish new from old...facilitate the visualization of specific proteins in cells. Tagged protein can easily be overexpressed from...techniques to follow translation in living single cells. However, before CRISPR-Cas9 these techniques were...interests, suspected to interact, are added to a cellular sample. Both antibodies have a short antibody ... turnover of specific endogenous proteins in any cell type. Exciting! Many thanks to our guest blogger... -
Viral Vectors 101: Viral Vector Elements
TypeBlog Post...available in the adenovirus section below! Fig. 2 - Viral vector components of AAV Adenovirus Adenoviruses...genetic cargo, typically an expression construct, to cells/organisms. This is often cDNA, shRNA, or something...perform very similar functions to infiltrate the host cell and deposit viral cargo. Gene expression While AAV...what will be delivered and expressed in the host cell from the transfer plasmid. Viral packaging and entry...altered tropism of AAV to target different tissue or cell types. AAV also requires some back up from adenovirus...promoter that you wish to deliver to your target cells. In adenovirus, the ITRs serve as a type of origin...deficient. This is typically supplied by the production cell line (HEK-293) during production. Fun fact: There... -
Plasmids 101: Cre-lox
TypeBlog Post.... PubMed PMID: 6276558. 2. Site-specific DNA recombination in mammalian cells by the Cre recombinase of...transgenic animals, embryonic stem cells, and/or tissue-specific cell types: Cre-lox recombination. What...downstream of promoters that are active only in certain cell or tissue types, during certain stages of development... recombinase can be expressed only in specified cells or at specified times. Combining this with some ...has been used to successfully introduce Cre into cells of interest. What if I need two separate recombination... -
Back to Bacteria: CRISPR gRNA Multiplexing Using tRNAs
TypeBlog Post...3570-5. doi: 10.1073/pnas.1420294112. Epub 2015 Mar 2. PubMed. Find the plasmids from this publication ...toolkit in human cells. Nissim L, Perli SD, Fridkin A, Perez-Pinera P, Lu TK. Mol Cell. 2014 May 22;54(...advantageous to instead use a preexisting, conserved cellular machinery to process gRNAs. Hijacking tRNA processing...tRNAs are among the most abundant molecules in a cell, this system is clearly also robust enough to ensure...54(4):698-710. doi: 10.1016/j.molcel.2014.04.022. Epub 2014 May 15. PubMed. Find the plasmids from this... -
Why and how to start studying chromatin (with Addgene's help)
TypeBlog Post...JS, Legube G, Miller KM Genes Dev. 2015 Jan 15;29(2):197-211. DNA Cross-Bridging Shapes a Single Nucleus... R, Schmalhorst PS, Jude JG, Zuber J, Gerlich DW Cell. 2017 Aug 24;170(5):956-972.e23 Screen identifies... R, Schmalhorst PS, Jude JG, Zuber J, Gerlich DW Cell. 2017 Aug 24;170(5):956-972.e23 Rapid and phosphoinositol-dependent... Rando OJ, Xue Y, Swiderek K, Kuo A, Crabtree GR Cell. 1998 Nov 25. 95(5):625-36. An architectural role..., Ensminger AW, Fox AH, Chess A, Lawrence JB Mol Cell. 2009 Mar 27;33(6):717-26. Reporter-nanobody fusions... -
27 Hot Plasmids from 2016
TypeBlog Post...backbone, which expresses the gRNA from a Drosophila U6:2 promoter and Cas9 from the actin 5C promoter. Addgene...backbones for lentivirus LV 1-5 and retrovirus RV 2-5 were constructed. The authors then used GMAP assembly...engineering (MAGE) (1). MAGE uses recombineering (2) to simultaneously incorporate multiple single-strand...number of tandemly expressed gRNAs respectively) and 2) the size of the deletion. Smaller deletions generally... HEK293FT cells expressing a single gRNA targeting a single gene. The gRNA expressing cells were then ...plasmid to generate a population of mutant cells. The mutant cells were treated with WNV at a dose and duration...regulate the ability of WNV to induce cell death in infected cells (SEL1L, UBE2J1, EMC3, EMC2, DERL2, UBE2G2... -
Plasmids 101: Sequence and Ligation Independent Cloning (SLIC)
TypeBlog Post..., but at a lower efficiency (~20%). Figure 2: Schematic of multicomponent assembly with SLIC. Multiple...bacteria, so it can be transformed as-is into cells. The cells then get to work fixing up the “damage” and...nicked plasmid together long enough to get it into cells and let them do the repair work. The key is T4 DNA... -
Sharing is Caring: But How to Distribute Open Hardware?
TypeBlog Post...-priced commercial devices. Fig. 2: Workflow for open software (left) vs. open hardware (right...quantitatively evaluating antibody staining, or counting cells are now routine, open-source software projects that...portable device for studying plankton using flow cells, has become an established alternative to high-priced... and blueprints has the potential not only to accelerate scientific progress, but also to enable science... -
Hot Plasmids and Viral Preps - March 2021
TypeBlog Post...endothelial cell-pericyte, neuron-astrocyte, and cancer-stromal cell pairs. Figure 2: Schematic...Winslow’s lab to label cells after cell-cell interactions. Using G-baToN, “sender” cells express GFP on the... and “receiver” cells express an anti-GFP nanobody on the cell surface. When the cells interact, GFP is...the receiver cell, and the receiver cell turns green. This system can be used in many cell types including...engineering with single-pot assembly Tracking cell-cell interactions New auxin inducible degron system....brgcm3sw New system developed to track cell-cell interactions By Jennifer Tsang GFP-based Touching...of the interaction between the sender cell and the receiver cell. Image from Tang et al., 2020. ... -
General Transfection
TypeProtocol... solution can be stored at 4 °C for up to 2 months. After 2 months, discard the tube and thaw a new working... transfected using 1:1, 1:2, 1:3 and 1:6 µg of pRosetta :µg of PEI. The 1:2 and 1:3 ratios provided high...Plate 1x10 6 cells in a 75 cm 2 flask in a volume of 15 mL. Wednesday: Plate 1x10 6 cells in a T75 flask... transfect cells with a fluorescent plasmid using a variety of ratios. Check the cells 1–2 days after ...optimized for viral production) Day 1: Transfect Cells Day 2 (am): 18 h post transfection - Remove media, ...tissue culture plates. Incubate the cells at 37 °C, 5% CO 2 for ~20 h. Gently aspirate media, add 10 mL...Biological Safety Cabinet 0.5–10 µL single channel pipette 2–20 µL single channel pipette 20–200 µL single channel... -
Mouse Modeling, Part 1: Genetically Engineered Mice
TypeBlog Post...covered in more detail in part 2 of this blog series) controls the cell types in which the conditional...modified zygotes or embryonic stem cells. Modified embryonic stem cells are injected into a blastocyst which...engineered cells. Similar to transgenic mice, knockout mice are engineered during the embryonic stem cell stage...not all cells in the blastocyst were successfully edited by the injection of embryonic stem cells. Also,... interest into a zygote, or into embryonic stem cells that are then injected into a blastocyst. There ...of interest into a zygote or into embryonic stem cells. Non-homologous recombination incorporates this ...targeting vector is electroporated into embryonic stem cells and this will insert the gene at a specific site... -
Tips for Titering Your Lentiviral Preps
TypeBlog Post...protocols 4.4 (2009): 495-505. PubMed PMID: 19300443. 2. Geraerts, Martine, et al. "Comparison of lentiviral...can actually infect cells. These assays typically involve infecting a target cell line with your virus...distinguish between a cell that has had one viral particle integrated into its genome and a cell that has had ...arrived; you’ve painstakingly cared for your packaging cell line, prepped your DNA, transfected and harvested...move ahead with your infection and make your stable cell line. While we’ve all experienced the pressure to...viral copies that have integrated into the target cell’s genome. Physical titer The two most common assays...functional titer uses FACS to count the number of target cells that are positive for vector encoded transgene expression... -
Summer SciComm Series: A PhD in Science Communication
TypeBlog Post...perceived climate change risks. Nature Climate Change, 2(10), 732-735. doi:10.1038/nclimate1547 Kunda, Z. (...spend the afternoon lovingly tending to the stem cells I was using in an experiment, then spend the evening... -
3 Challenges in Plant Synthetic Biology
TypeBlog Post...and open a new conversation about GMOs. Challenge #2: Technical obstacles to plant synthetic biology In...challenging to engineer a specific function in these multicellular organisms. However, the rewards are great if... -
Lentivirus ddPCR Titration
TypeProtocol...Activation 95 10 2 1 Denaturation 94 0.5 2 40 Annealing/Extension 60 1 2 40 Enzyme Deactivation 98 10 2 1 Hold ...copies of RPP30 in diploid cells, thus the reason for multiplying by 2. $$V = 2*{copies\ RRE \over copies...diluted 2-fold serially, the concentration of RRE positive droplets should decrease by a factor of 2 across...each well. Detach cells by incubating with 200 µL TrypLE for 1–2 min. Resuspend cells in 500 µL DMEM complete...Lentivirus is generally considered biosafety level 2+. Please ensure that you are in compliance with your...channel pipette 200–1000 µL single channel pipette 2–50 µL multichannel pipette 20–200 µL multichannel ... DG8 cartridge into the cartridge holder. Using a 2–50 µL multichannel pipet, load 20 µL of the reaction... -
Plasmids 101: The protein expression toolbox
TypeBlog Post... the transcriptional level. Fig. 2 Tetracycline on/off promoters and modes of action ...force to control protein expression in mammalian cells: easy to use biological tools are abundant! In this...tag prior to introduction of the construct into cells. However, if you would like tunable control of an... -
Announcing the Winners of the 2021 Michael Davidson and Roger Tsien Commemorative Conference Awards
TypeBlog Post...processes that happen inside the cell,” says Pedre Pérez. Figure 2: Micrographs of the biosensor ...sensitive GFP2 (roGFP2)-based biosensors for live cells. His work focuses on the enzyme hydropersulfide-...biosensor expressed in the human cell line, Hep3B. From left to right: Mitotracker Red, GFP for the biosensor,...studies opioid use disorder. Her goal is to identify cell populations in the brain that contribute to the ...will explore the connectivity patterns of these cells and the functional contribution to a variety of ...administration and withdrawal to explore how these cells may encode the negative affect associated with drug...library of mutant sensors expressed in a mammalian cell line engineered to be electrically excitable. The... -
RNA Extraction Without A Kit
TypeBlog Post...156–159. https://doi.org/10.1016/0003-2697(87)90021-2 Chomczynski P, Sacchi N (2006) The single-step method...are commonly found in cells, and without something to block RNase activity upon cell lysis, RNA is degraded...RNases such as RNaseZAP. When harvesting tissues, cells, plants, fungi, or bacteria, keep samples cold and...before RNases had a chance to break down RNA upon cell lysis. In the late 1970’s, Chirgwin and colleagues...keeping your samples cold until homogenization and cell lysis. This can be challenging depending on your...developed ways to “stabilize” RNA within tissues before cell lysis. These products, namely RNAlater® from Thermo...solutions that work by inhibiting RNase activity within cells or tissues- they don’t actually chemically stabilize... -
Antibodies 101: Affinity Reagents
TypeBlog Post...Antibody Fragments. Antibodies (Basel). 2019 Apr 9;8(2):28. doi: 10.3390/antib8020028. PMID: 31544834; PMCID...in transfected eukaryotic cells, allowing for them to be used as intracellular inhibitors. Aptamers are...the kids say) affinity reagents deserved to be celebrated, there are many other amazing affinity reagents...small enough to be expressed in bacterial and other cell systems. Since the majority of these alternative...the constant region. Nonspecific binding, caused cell receptors for the constant region, is also reduced..., peptides, amino acids, drugs, metal ions, and cells. They can be used either with or as fluorophores... may sound. Validated antibodies are still an excellent option for many applications, and frankly, if ... -
Lentivirus Production
TypeProtocol... solution can be stored at 4 °C for up to 2 months. After 2 months, discard the tube and thaw a new working...μg total DNA to μg PEI ratios of 1:1, 1:2, 1:3 and 1:6. The 1:2 and 1:3 total DNA:PEI μg ratios provided... transfect cells with a fluorescent plasmid using a variety of ratios. Check the cells 1-2 days after ...Transfect packaging cells Day 2 (am): 18 h post-transfection. Remove media, replace with fresh media. ...Biological Safety Cabinet 0.5–10 µL single channel pipette 2–20 µL single channel pipette 20–200 µL single channel... 200–1000 µL single channel pipette Ice bucket CO 2 incubator Pipet controller Hazardous waste container..., 5% CO 2 for ~20 h. Prepare a mixture of the three transfection plasmids into OptiPro SFM: Reagent Amount... -
Affinity Purification of Recombinant Antibodies with Protein A or Protein G
TypeProtocol...phosphate monobasic monohydrate (NaH 2 PO 4 ∙H 2 O), pH 7.0 138 g NaH 2 PO 4 ∙H 2 O 1 L deionized water Adjust...sodium phosphate dibasic (NaH 2 PO 4 ), pH 7.0 142 g of NaH 2 PO 4 ∙H 2 O 1 L deionized water Adjust pH...monobasic monohydrate (NaH 2 PO 4 ∙H 2 O) 610 mL of sterile sodium phosphate dibasic (NaH 2 PO 4 ) Store up to...recombinant antibody. Section 2: Buffer exchange Choose Option 1 or Option 2 based on the concentration ...antibodies. Workflow Timeline Day 1: Purify antibody Day 2 or later: Buffer exchange Equipment Class II, Type...conical tubes NanoDrop spectrophotometer 37 °C, 5% CO 2 incubator with shaking platform set to 120 rpm 37 ... channel pipette 20–200 µL single channel pipette 2–20 µL single channel pipette Reagents Aspirating pipette... -
Addgene: The First Twenty Years
TypeBlog Post...beginning Let’s take a quick flash back to 2004. “Shrek 2” was the most popular movie in theaters, the Razr ...amazing years in front of us. So in our last celebratory moment, we wanted to walk through some of our...Facebook and Gmail, were launched. And Melina Fan, a cell biology graduate student, was frustrated by the ...to receive the Massachusetts Nonprofit Network Excellence Award for our electronic MTA system. We also ...now our Sr. Director of Production) pie-fully celebrating Addgene's 10 year anniversary. Expanding... -
Plan Your Experiment
TypeGuide... or (2) a lack of efficient target cleavage in cells expressing both Cas9 and gRNA. Edited cells may be...expressed in your target cells. For easy-to-transfect cell types (e.g. HEK293 cells), transfection with standard... CRISPR machinery. For more difficult cells (e.g. primary cells), viral delivery of CRISPR reagents may...identify and enrich positive cells, or selection marker to generate stable cell lines (for details, see Plasmids...wide variety of mammalian cell lines Useful for difficult to transfect cell types, can also be used in...possible genotypes within the resulting cell population. Some cells may be wild type due to either (1) a ...will use the example of CRISPR/Cas9 in mammalian cells, many of these principles apply to using CRISPR ... -
Hot Plasmids - October 2020
TypeBlog Post...localizations. Figure 2: Split-wrmScarlet labeling proteins with different subcellular locations. Image from...determine cell cycle length by examining the ratio of blue to red cells. Cells undergoing rapid cell cycles...engineered C. elegans cell lines to express wrmScarlet1-10 unattached to any other cellular protein. They used...’s difficult to observe the cell cycle in vivo, particularly if the cells are migratory or in deep tissues... BaF3 cells were transduced with H2B-FT virus and grown in varying concentrations of IL-3. Cells grown...proportion of blue fluorescence, indicating cell proliferation. BaF3 cells maintained in media without IL-3 show...H2B-FT consistently predicted the cell cycle speed across these different cell types. In one example, H2B-FT... -
CRISPR 101: Mammalian Expression Systems and Delivery Methods
TypeBlog Post... already have an end product in mind, steps 1 and 2 will generally be straightforward. Likewise for step...Calcium phosphate Cells Transformed cell lines Transformed cell lines Transformed cell lines Cargo Nucleic...identify and enrich positive cells or a selection marker to generate stable cell lines. Transient or stable...and enrich positive cells. Likely contains a selection marker to generate stable cell lines. Packaging and...wide variety of mammalian cell lines. Useful for difficult to transfect cell types and can be used in ...protein are degraded within the cell. Delivery methods for mammalian cell lines As mentioned above, the...components into your target cells. Delivery of these components into mammalian cell lines is quite broad and... -
The CRISPR Software Matchmaker: A New Tool for Choosing the Best CRISPR Software for Your Needs
TypeBlog Post... tabular HTML formatted output. Surprisingly only 2 tools provide FASTA output. A few notable tools allow...Nature biotechnology(2014). PubMed PMID: 24880488. 2. Hsu, Patrick D., et al. "DNA targeting specificity...the research community. I’ve likened it to the celebration surrounding the piñata. From the perspective ... -
CRISPR in the Clinic
TypeBlog Post... Cure for HIV/AIDS. Int J Mol Sci. 2023 Jan 13;24(2):1563. doi: 10.3390/ijms24021563 Resources on Addgene.org...Cas9 in Intestinal Stem Cell Organoids of Cystic Fibrosis Patients." Cell Stem Cell. 13, 653-658 (2013). ...patient’s own cells that have been modified ex vivo, previously edited healthy donor cells can be delivered...Genetic Disease in Mouse Via Use of CRISPR/Cas9." Cell Stem Cell. 13, 659-662 (2013). Gerald Schwank et al. ...on editing animal models of disease and cultured cells. For example, in 2013, Jinsong Li and colleagues...applied CRISPR to disease correction in adult stem cells isolated from two patients with cystic fibrosis ...delivery directly to the patient. Patient-derived cells can alternatively be harvested, edited ex vivo, ... -
Hot Plasmids May 2018 - Optogenetics, Decaffeination, Biosensors, and Fluorescent Protein Tools
TypeBlog Post...C-terminus of human codon-optimized cryptochrome 2 (CRY2) from Arabidopsis thaliana. When exposed to ...illumination of neighboring cells evokes action potentials (APs) in patched cells expressing wild type CoChR...techniques for live-cell imaging of the dynamic changes in biochemical activity within the cell. Their Fluorescence...distribution of clusters without accumulation in subcellular compartments such as nuclear speckles. Furthermore...OptoSTIM1), caused two-fold faster changes in intracellular Ca2+ levels than the original version containing...CRY2clust should prove a useful tool to further probe cellular function. The CRY2clust Plasmid can be found here...28646204. soCoChR: A novel opsin that enables single-cell optogenetics Article contributed by Meghan Rego ... -
Split-BioID: An Improved Method for Studying Protein-Protein Interactions
TypeBlog Post...dimerization-dependent protein interactions. FEBS letters, 591 2, 415-424. PubMed PMID: 28032891. This is a different... expressed in cells via plasmids or by the creation of stable cell lines and these cells are then grown... complex. Not performed in a native cell context. For AP-MS, cells are lysed before the bait protein is...and interacting proteins in mammalian cells. The Journal of cell biology. PubMed PMID: 22412018. PubMed...against PPIs that aren't stable outside the native cell context. The Split-BioID method Enter Split-BioID...tagging of proteins in both BioID or Split-BioID, cells are lysed, protein extracted, and labeled protein...proteins that interact with the bait in a native cell contact. Other PPI methods may require protein interactions... -
Choosing a CRISPR Nuclease: Site Accessibility, Specificity, and Sensitivity
TypeBlog Post...divided by the off-target activity. Figure 2: Specificity is the measure of off-target activity...CRISPR-Cas12b for mammalian genome engineering." Cell discovery 4.1 (2018): 63. PubMed PMID: 30510770.... -
Channelrhodopsins with improved light sensitivity for minimally-invasive optogenetics
TypeBlog Post...still depolarize neurons at lower MOIs. Figure 2: ChRgers are delivered by intravenous injection into... channels in living cells. Multiple properties of a channelrhodopsin, such as cell localization, kinetics... -
Getting Started with Behavioral Neuroscience: Standardizing Experiments and Using Viral Vectors
TypeBlog Post...main decisions to make: 1. Which modification? and 2. Which viral vector should be used? Modifying gene...Different AAV serotypes have preferences for specific cell types. For example, AAV1 and AAV9 serotypes have...most cases with VSV-G that generally mediates broad cell tropism and has a high percentage of neuronal targeting... -
Fluorescence Titering Assay
TypeProtocol...method 2): Method 1 Method 2 $$T = {N*F*D\over V_T}$$ Where: T = Titer, TU/mL N = Number of cells transduced...Workflow Timeline Day 0: Seed 293T cells Day 1: Transduce cells Day 2 (am): Remove media, replace with ...,000 cells into 14 mL of DMEM complete. Mix well by pipetting or inverting. Aliquot 2 mL of cell suspension...fluorescent cells Equipment Class II, Type A2 Biological Safety Cabinet 0.5–10 µL single channel pipette 2–20 ...Lentivirus is generally considered biosafety level 2+. Please ensure that you are in compliance with your... 200–1000 µL single channel pipette Ice bucket CO 2 incubator Pipet controller Hazardous waste container...added to 150,000 cells resulted in 25% fluorescent cells, then the titer is: (150,000 cells x 0.25 fluorescent... -
Adapting Toehold Switches to Detect Zika Virus
TypeBlog Post...Components." Cell (2016). PubMed PMID: 27160350. Find Plasmids from the publication at Addgene 2. Green, ...circuits to be deployed out of the laboratory in a cell-free and biosafe format that was stable for up to...possible and submitted our manuscript to the journal Cell just six weeks later. The Zika publication timeline...of Toronto. His research is focused on developing cell-free synthetic biology applications for human health...de-novo-designed regulators of gene expression." Cell 159.4 (2014): 925-939. PubMed PMID: 25417166. PubMed...Keith, et al. "Paper-based synthetic gene networks." Cell 159.4 (2014): 940-954. PubMed PMID: 25417167. PubMed... -
Western Blot
TypeProtocol...protein from cells or tissue samples. Equipment Microcentrifuge 0.5–10 µL single channel pipette 2–20 µL single...transfer, block, incubate with primary antibody Day 2: Incubate with secondary antibody Video Watch this...Heat block Mini gel tank chamber Power supply iBlot 2 Gel Transfer Device Roller Spatula Platform shaker...running buffer Prestained protein ladder Ethanol iBlot 2 PVDF Mini Stack, Thermo Fisher IB24002 20X TBS Tween...immediately or store at -80 °C until ready to use. Section 2: Determine the total protein concentration and prepare...in deionized water. To prepare 20% ethanol, dilute 2 mL of ethanol into 8 mL of deionized water and mix...the transfer sandwich as follows: Unseal the iBlot 2 PVDF Mini transfer stack. Set the Top Stack to one... -
Open Resources and Plasmid Tools For Studying C. elegans
TypeBlog Post...unc- 119 + selection." MicroPublication 1 (2018): 2–3. Wang, Han, et al. "cGAL, a temperature-robust GAL4...currently doing this using two approaches: single-cell RNA-sequencing to identify neuronal class and deep...WDDD aims to acquire quantitative data on all the cell divisions of the C. elegans embryo when all essential...Wang et al., 2018).” With the split system, only cells that have both halves of cGAL can drive expression...