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  1. Tips for Getting a Faculty Position

    Type
    Blog Post
    ...personal litmus test was whether my wife could explain what I was proposing. The result of my test was humbling... your candidacy. A major reason that a lot of candidates either get no interviews, or get several interviews...accomplish. No matter how many times I say this, candidates regularly try to convince me that their search...language as possible. Seriously. My suggested litmus test is whether your friend in a lab outside of your ... and therapies." This is only the first few minutes of the chalk talk. Realize that it is rare to make...available here for free!) contains strategies, hints, anecdotes, and insights. After I wrote the first version... Jennifer Lippincott-Schwartz at the National Institutes of Health, was an Associate Professor at Albert...
  2. Sleeping Beauty Awakens for Genome Engineering

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    Blog Post
    ...DNA with a TA dinucleotide (there are many such sites in the human genome). The original plasmid is empty... then degraded by the cell.4.) The transposase creates a double strand break in the DNA and allows the...has been designed to perform gene transfer in vertebrates. The system is comprised of 2 components: 1) ...number of extinct transposon sequences and then testing various combinations of changes. The basic functional.... The vectors each contain two SfiI restriction sites with different overhangs depending upon whether ... Feb 4. doi: 10.1002/biot.201400821. PubMed. 2. Mates L, et al. Molecular evolution of a novel hyperactive...transposase enables robust stable gene transfer in vertebrates. Nat Genet. 2009 Jun;41(6):753-61. Epub 2009 ...
  3. Troubleshooting and Optimizing a Western Blot

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    Blog Post
    ... incubation (10–20 minutes) at 70 °C, or a truly lengthy incubation (30–60 minutes) at 37 °C, if you suspect...DNA-binding proteins, you may need to sonicate your lysates in order to release the proteins from their binding...in your background, try asking more experienced labmates or looking it up online. You’ll find many resources...your timer to ding. If you’re shaving off a few minutes here and there, and seeing high background in your...antibodies). You’ll want to run a protein gradient to test the antibody at the recommended dilution. If the...concentration decreases).     Figure 3: Testing the antibody’s dynamic range. A) The protein dilutions...from 1:100–1:1,000. If your antibodies come from ascites fluid, try a dilution range from 1:1,000–1:100,...
  4. Even more elegant: Single injection CRISPR/Cas9 in C. elegans

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    Blog Post
    ...for the targeted gene. After initial testing, Dickinson et al. tested this system across 7 genes in parallel...remove after injection, they added flanking loxP sites and a heat-shock inducible Cre to generate a self-excising...worms have laid eggs, hygromycin is added to the plates to select for candidate knock-ins. These candidate... is inserted at the 5’ end of a gene, the SEC separates the targeted gene from its promoter, creating ...protein in the C. elegans genome. Although they tested fluorescent protein fusions, this system could ...editing using linear DNAs with microhomology to Cas9 Sites in Caenorhabditis elegans. Paix A, Wang Y, Smith...
  5. Three Tips for Preventing Viral Plasmid Recombination in Your Samples

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    Blog Post
    ...growth and DNA yield. Test multiple, small colonies After streaking LB agar plates, you may notice that...vectors (LTRs and ITRs), plasmids with multiple polyA sites, and other plasmids that contain repeating elements...how to amplify recombination-prone plasmids and testing your prep can save you the headache of troubleshooting...cultures contain the recombined vector backbone. Test multiple colonies before saving a glycerol stock...you can try re-streaking for single colonies and testing multiple preps. In some cases, we suggest gel extraction...the recombined plasmid is still visible. This indicates that the DNA prep contains a mixture of the full...
  6. Plasmids 101: TOPO Cloning

    Type
    Blog Post
    ...your incubation time on ice to 5 minutes (incubating the full 30 minutes will not significantly improve ...standard primers (no need to add unique restriction sites on the ends) and amplify your sequence of interest...the PCR product and TOPO Vector.  3. Incubate 5 Minutes at Room Temperature: You can place your reaction...digest, or sequencing. Pro tips Do not add 5’ phosphates to your PCR primers; you need that free hydroxyl...functionality are used in place of Taq to reduce error rates; however, proofreading polymerases will also remove...); however, you may need to incubate for 20-30 minutes if your PCR product is at a low concentration or...
  7. Hot Plasmids: FRET-Based Biosensors

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    Blog Post
    .... It’s a problem that he considers “one of the greatest challenges of neuroscience.”  Hot plasmids: Twitch...inside cells that are on the move, such as T lymphocytes. Griesbeck and his colleagues began by isolating...version of the protein with as few calcium-binding sites as possible for added sensitivity. As reported in...these Twitch sensor variants were optimized by testing various linker configurations in a large-scale ...and high resolution functional tracking of T lymphocytes, too, making them a versatile tool for application...other people start using it. For us, it’s like a test.” References Thestrup et al. Optimized ratiometric... functional in vivo imaging of neurons and T lymphocytes. Nat Methods. 2014 Jan 5. doi: 10.1038/nmeth.2773...
  8. Scientific Reproducibility - Focusing on Solutions at the Minisymposium on Reproducibility

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    Blog Post
    ...research tools. BenchSci collates information about antibodies while FPbase curates information about fluorescent...sometimes formulating new biological concepts. However, rates of reproducibility for preclinical studies, as reported...Project: Cancer Biology have produced similarly low rates of reproducibility. Failed attempts to apply irreproducible... to future work cost both time and money with estimates reaching in the billions of dollars (Freedman ...making it easier to retain searchable, thorough notes on how lab procedures were actually performed, potentially... The publication record will then show that the tested hypothesis is correct (a great success story) even...category include performing experiments with too few replicates leading to suspect statistical significance (...
  9. Viral Vectors 101: Optogenetic Tools

    Type
    Blog Post
    ...reinhardtii. When exposed to blue light, this channel activates neuronal activity by opening and allowing positively...conformational change in the extracellular domain which activates the native signaling cascade of the intracellular...conformational change when exposed to blue-light and activates downstream secondary signaling pathways. Photoswitchable...light, the ligand engages the binding pocket and activates the receptor. Created with BioRender.com. ...factors will help you determine which one(s) are candidates for your experiments.  Wavelengths Most vectors...et al., 2019) for each tool, and you may have to test and optimize the intensities of light sources used... frequencies (Zhang & Cui, 2015). You’ll need to test for these differences when designing your experiment...
  10. How to Lead a Great Meeting

    Type
    Blog Post
    ... an entire experiment and delegate tasks to lab mates or to discuss a potential new research direction... regular check-ins with their employees. 15-30 minutes weekly or monthly will usually suffice to keep ...Managers will get a sense of the employee’s workload, updates on current projects, and offer feedback. The employee...anything that is missing.  During the meeting, take notes on the agenda points. At Addgene, we like to do ...Before leaving the meeting, skim back through your notes and pick out the action items. Move them into a ... positive peer pressure to make sure everyone completes their assigned items to keep the project moving...scope” above) or if you can cut it down to thirty minutes. Keep it moving: If you tend to get stuck diving...
  11. Addgene-Seeding Labs plasmid grant round 3: microbial drug resistance and biofilms, antidiabetic plant components, visualizing brain injury - and a glowing robot fish

    Type
    Blog Post
    ...collection of pathogenic Klebsiella and Pseudomonas isolates causing urinary tract infections. This project... for plant compounds to treat complications of diabetes Gloria Otito Izu, PhD Candidate, University of... the major pathophysiological complications of diabetes mellitus. Recombinant human proteins that play...play a role in insulin regulation and diabetes will be expressed from plasmids (find more information on...of the plant compounds on these proteins will be tested. Investigating changes in neuronal activity after...Armenia Gohar Tsakanova is a Senior Researcher who investigates the molecular and cellular etiopathomechanisms...projects progress. Subscribe to the Addgene blog for updates and future collaborations. Many thanks to all of...
  12. Photosensitizer Induced Cell Ablation with FAP-TAP MG-2I-dL5**

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    Blog Post
    ...Light-induced cell ablation with MG-2I-dL5** He et al tested out light-induced cell ablation with MG-2I-dL5*...dye and exposed to light stained dead within 30 minutes of exposure. 90 seconds of illumination were sufficient... fish with the dye. Embryos exposed to just 12 minutes of illumination had fewer mCer3-labeled cells in...cells.  He et al also show that MG-2I-dL5** only generates small amounts of non-specific ROS when exposed... red fluorescent photosensitizer protein that generates ROS when illuminated with green light. They found...that KillerRed required longer exposure times (5 minutes vs 10 seconds) to achieve the same level of killing...cell nuclei. The two photosensitizers had similar rates of off-target damage to neighboring cells. TL;DR...
  13. Visualizing Genomic Loci with CRISPR-Sirius

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    Blog Post
    ...nuclear processes. The latest of these visualization tools is CRISPR-Sirius, the brightest CRISPR-based tool...CRISPRainbow allows for simultaneous visualization of sites on different chromosomes in living cells, the system...PP7, or boxB sequences inserted into the sgRNA generates blue, green, or red colors for labeling. A combination...in CRISPRainbow, they knew they could be good candidates for further development. They inserted an octet...three loci and measure inter-locus distances. They tested this system out on chromosome 19 by targeting 46... the National Academy of Sciences of the United States of America 112 10 (2015): 3002-7. PubMed PMID: ...
  14. Multiplex Genome Editing with CRISPR-Cpf1

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    Blog Post
    ...processing, i.e. tRNAs or Csy4 cleavage sites. This eliminates bulk from crRNA expression plasmids resulting...et al   Multiplexed Lentiviral Expression Cassettes lentiviral transduction One vector expresses... own promoter   Kabadi et al Csy4-Cleavable Cassettes transfection gRNAs expressed from a polycistronic...co-transfection of Cas9 Nissim et alTsai et al PTG Cassettes transfection gRNAs expressed from a polycistronic...s ability to process its own pre-crRNA arrays eliminates the need to include multiple promoters to drive...Multiplex gene editing with CRISPR-Cpf1 is one of the latest developments in CRISPR technologies.  It’s a simple...
  15. Plasmids 101: Inducible Promoters

    Type
    Blog Post
    ...a versatile tool developed for use in prokaryotes and eukaryotes, works via direct activation. In this...conformational change that removes it from lacO sites within the promoter and ceases repression of the... absent, regulatory protein AraC binds O and I1 sites upstream of pBad, blocking transcription. The addition...addition of arabinose causes AraC to bind I1 and I2 sites, allowing transcription to begin. In addition to...CAP) can also stimulate AraC binding to I1 and I2 sites. Supplementing cell growth media with glucose decreases...sensing protein YFI. When light is absent, YFI phosphorylates FixJ, which binds to the FixK2 promoter to ...
  16. Sweating the Small Stuff: Details in the Lab

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    Blog Post
    ...What is the universal thing that unites all scientists? Curiosity? Passion? A love of learning? No. Or... Or at least not entirely. What truly unites us all is the frustration of an experiment failing because...experiment (labeling tubes never takes longer than 5 minutes, right?) As a result, I’d always end up stressed...differently.  Tools to Try  Checklists Found in surgical suites, air fields, and military bases, checklists are... at as you work. Draw your plate maps onto your plates, alongside your physical copy. If you’ve got messy...workspace and your workflow can have a huge impact. Test different approaches, like whether it's better for... forever grateful, I started setting aside 3-5 minutes to sit quietly at my bench before the start of ...
  17. A History of Genome Engineering in Popular Culture

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    Blog Post
    ...of animal testing and modifications. The premise of the novel involves Dr. Moreau who creates human-animal...acid recognition sites had to be designed each time we wanted to target new genomic sites. The discovery...proteins are characterized by large DNA recognition sites, which makes them highly specific.  Jurassic Park..., CBE and ABE have obviated the indel formation rates that are typically associated with the DSBs and ...that were “affected by CRISPR.”  Prime editing The latest breakthrough in genome editing is prime editing...intracellular pangenesis to the rediscovery of Mendel. Comptes Rendus de l’Académie des Sciences - Series III ...
  18. Addgene's Tips for Plasmid Quality Control

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    Blog Post
    ...DNA-editing software which integrates our database of over 2000 primers. Two 96-well PCR plates are prepared with...samples through our lab using barcoded tubes and plates. The critical pieces of information for a given...functional mutations, antibiotic resistance, restriction sites used during cloning, and most importantly, the predicted... in-frame protein fusions, and multiple cloning sites. In the simplest case we have a standard backbone... purifying the DNA and gives comparable success rates and sequence quality, which is critical for the ...100 µl of glycerol stock to each of 2 96-well microplates (identical copies, see image above). We then ...
  19. Human Germline Editing Using CRISPR

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    Blog Post
    ... conduct microinjection experiments in S phase zygotes at 18 hr post fertilization. They observed higher...co-injected CRISPR machinery with sperm into M phase oocytes, thus allowing repair to take place before DNA ...embryos proceeded to the blastocyst stage at similar rates to untreated controls. Ma et al. performed sequencing...sequencing of 23 potential off-target editing sites in the embryos, as well as whole exome sequencing of ...However, it is important to consider that already-tested CRISPR alternatives are applicable in many situations...surrounding CRISPR-based therapy is the level of testing needed to define whether off-target editing or ...like to target. In addition, as on-target editing rates vary widely from gRNA to gRNA, it’s unclear where...
  20. Plasmids 101: Modular Cloning

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    Blog Post
    ...functional units which are transcribed together. Image courtesy of Robert Hurt. Understanding how individual...Figure 2: The three assembly levels of MoClo. Image courtesy of Rob Hurt. What makes MoClo systems so powerful...optimizing a TU is much easier when you can quickly test that part in different contexts and plug different...products. The flexible nature of MoClo allows users to test a variety of different orientations and components...best promoter for a given peptide can easily be tested by generating Level 1 TUs with unique promoters...modifying enzyme) to pair with it can be queried by testing any number in the Level 2 assembly. These pathways...attractive! It allows researchers to assemble and test many variables all at once. CRISPR CRISPR arrays...
Showing: 241 - 260 of 934 results