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Showing: 221 - 240 of 985 results
  1. New Optimized Genome-wide CRISPRko, CRISPRi, and CRISPRa Libraries

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    Blog Post
    ...These libraries utilize optimized sgRNAs that were designed based on the rules identified in Doench et al....1,000 non-coding control sgRNAs. This library was designed to improve on-target activity while reducing off-target...with 6 sgRNAS, highlighting the benefit of sgRNA design in CRISPR libraries. Thus, the Brunello library... that if an essential gene plays a role in the desired screening phenotype, it may be missed because it's... the sgRNA metrics, confirming again that sgRNA design plays a significant role in library efficiency....CRISPRa, sgRNAs were targeted between 150-75 nucleotides upstream of the TSS. Similar to the Brunello ...Activation Mediator) uses an improved activator design that consists of inactive Cas9-VP64, a sgRNA with...
  2. Tips for Writing a Good Cover Letter

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    Blog Post
    ... about! You could describe your organizational system, your rationale for designing it the way you did...experience and skills would help you do the job as described. Let’s imagine you’re applying to a job that ... your cover letter, you can expand on that by describing how you developed and used a ddPCR assay to answer...question. Now, the hiring manager knows that you can design experiments with ddPCR, interpret the results, ...start by looking at the requirements in the job description. For each requirement, ask yourself if you have...to their work. Since the beginning is often the hardest part, here are some examples to get you started...company/organization]. I am a [adjective that describes you] scientist with over [number] years of experience...
  3. CRISPR 101: Which Cas9 Do I Choose for My CRISPR Experiment?

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    Blog Post
    ...vectors and design your sgRNA targeting sequence using one of the many freely available sgRNA design programs...many cases several exons’ worth of DNA. Any ∼20 nucleotides of DNA can serve as the target for Cas9’s single...Cas9 localizes the deaminase to where the edit is desired, and it performs the programmed edit within the...flexibility. A consideration with this tool is that the desired edit will be performed on all relevant bases within...system utilizes an RNA template containing the desired edit adjoined to the sgRNA, a reverse transcriptase...not require an expertly positioned PAM without undesired bases nearby that may undergo unwanted editing....   Ok, I have a Cas9! What do i do next? Designing or selecting a sgRNA Addgene may carry a validated...
  4. Fluorescent Proteins 101: Aptamer Fluorophores

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    Blog Post
    ...Researchers have used oligonucleotides in fluorescent visualization techniques for decades, most notably for... exponential enrichment (SELEX), some 1010 oligonucleotides could be screened for their affinity to a ...aptamers as well, and over the course of the next two decades, these nucleotide-based ligand binders would prove...their broad range of targets, including proteins, peptides, amino acids, drugs, metal ions, and cells (even...counterparts, antibodies and enzymes, such as: Design and selection for targets can be done largely in...such techniques can be problematic, however. Well designed aptamers can help reduce such background, thereby...relatively bulky. One of the advantages of oligonucleotides over proteins is their modularity, which is...
  5. The Challenges of Cell Culture

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    Blog Post
    ...contamination and match their original description. The oldest, largest, and most diverse of these repositories...culture in the present day Cell culture is a widespread tool used in the fields of oncology, virology...problems surrounding cell culture over the last few decades some pharmacologists have tended to avoid cell ...International Cell Line Authentication Committee includes a database listing all cross contaminated or misidentified...comparable studies to be performed on a cell line even decades after it is initially isolated. Regrettably this...Master and Working stocks to work from. The future Attitudes are changing but yet more is needed to convince...can be prevented and we can progress faster to desired clinical endpoints.   Nick Amiss is an ATCC Outreach...
  6. Filming Science Videos in the Age of Social Distancing

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    Blog Post
    ...Good as a WFH desk, and as a video control center.   Cycle 2: Zooming Forward Design: We produced ... So, much like SynBio, it was time to start our Design-Build-Test-Learn cycles. If you’re not familiar...again. Here’s that process!   Figure 1: The Design-Build-Test-Learn cycle adapted for video making...through. I know cameras, but we needed someone else. Design: Jennifer thankfully volunteered, and we decided...here, the operator is in a different room.   Design: The previous cycle made me realize we needed to...restrictions in place, most importantly, masks.  Besides the muffled voices beneath masks, humans rely on...reach for Addgene.  So, onto research! I needed to design a system that would allow me to set up a camera...
  7. Hot Biosensors 2022: Year-End Roundup

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    Blog Post
    ...Addgene’s catalog is a new class of sensors for neuropeptides and neurotransmitters. Motivated to develop ...GPCRs recognizing various neurotransmitters, neuropeptides and other ligands - almost A to Z! - from ATP...a new preprint, Jared Toettcher and colleagues describe pYtags, a modular system for monitoring specific... tool for monitoring RTK signaling.  Figure 4: Design of pYtag fluorescent biosensors for monitoring ...iGECInano plasmids here!   Matlashov ME, et al. Design and Initial Characterization of a Small Near-Infrared...intermediate affinities from 40 to 140 mM. These new designs greatly broaden the options for potassium biosensors...further engineering. Figure 5: Structure-guided design and genome mining both led to new sensors with ...
  8. Plasmids 101: Common Lab E. coli Strains

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    Blog Post
    ...suggests there are hundreds. This only includes general lab strains designed for subcloning or protein expression...was updated on Nov 14, 2017. You've worked hard designing your plasmid – you carefully selected the optimal...Dr. Theodor Escherich, the scientist who first described them in 1885. E. coli are mainly found in the ...commercial lab strains of E. coli used today are descended from two individual isolates, the K-12 strain ...mutations found in E.coli strains Gene(s) Description Functional Consequence dam DNA adenine methylase... fertility plasmid. A low copy-number plasmid, encodes proteins needed for bacterial conjugation. Genes...resistance to tetracycline Additionally, Table 2 provides a quick reference for some of the popular strains...
  9. Viral Vectors 101: Biosensors

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    Blog Post
    ...have pre-designed plasmids for these systems! Ion sensors One common biosensor class is designed to monitor...all have specific sensors designed for them. For example, this class includes tension monitors associated...interest for many disciplines! Most of the sensors designed for calcium generate a fluorescent output, which... fluorescence in the presence of calcium. This includes FRET-based sensors such as Twitch. While calcium.... Physiological factors Unlike the previously described sensors, this class measures either factors as...to use them, you’ll need to use the vectors (or redesign the tools). It’s a good thing, though! Viral delivery...
  10. Improved Plasmid Maps Powered by SnapGene

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    Blog Post
    ...please improve your plasmid maps!" After thoughtful design, vetting, and tweaking, we’re excited to announce...identifies plasmid features that differ by only a few nucleotides, such as the fluorescent proteins EGFP and mEGFP... software. In fact, SnapGene’s feature library includes nearly 3x as many features as could be detected...greater than our previous mapping software and now includes Type IIS restriction enzymes that are commonly...the gene, the name of its gene product, and a description of its function. You can also click one location...enzymes that cut the given sequence. The table includes enzyme names, the locations where the enzymes ...features detected in the plasmid sequence. The table includes feature names, locations, sizes, colors used to...
  11. REPLACR Mutagenesis: Replacing In Vitro Recombination Methods

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    Blog Post
    ...discussed methods. As described above, you design two primers, each containing the desired mutations, to amplify...make a point mutation, you design two oligonucleotide primers with the desired mutation, then use those ... figure above shows guidelines for primer design; a desired insertion should be present in both primers...vitro recombination. Across all modifications described in Trehan et al., REPLACR-mutagenesis’ median ...
  12. Troubleshooting Your Plasmid Cloning Experiment

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    Blog Post
    ...coveted plasmid with no substantial delays. Design, design, design Before diving into the experimental work...experimental work. Fragments generation After you’ve designed your cloning scheme, you’re now ready to generate... to use 1-2 ug of the vector for digestion. PCR Design primers that overlap at least 24 bp with the template...from a large genome, you can recheck your primer design or optimize your primers or PCR conditions. Purifying...second and more detailed look at your experimental design. Full lawn of cells. The antibiotic in your plate...complementary to standard sequencing primers. If not, design primers to sequence your insert. When you get your...
  13. Channelrhodopsins with improved light sensitivity for minimally-invasive optogenetics

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    Blog Post
    ... model to help them construct “designer” channelrhodopsins with desired characteristics. The model was...Viviana Gradinaru’s lab used machine learning to design new channelrhodopsins that are more light sensitive...constrained and poorly understood. It’s hard to design new channelrhodopsins with high-throughput proteins...Using machine-learning to overcome channelrhodopsin design challenges To overcome these challenges, the Arnold...experiments. The sequences in this library were designed using structural information about parental channelrhodopsins...existing channelrhodopsins CoChR and/or ChR2(H134R). Designer channelrhodopsins paired with a systemic AAV allow...Find our chemogenetics and optogenetics science guides ...
  14. Important Considerations When Using AAVs

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    Blog Post
    ...utilizing chemogenetics (Designer Receptors Exclusively Activated By Designer Drugs, DREADDs) and optogenetics...beg the question: is axonal transport desirable or not desirable? If diffuse gene expression is tolerated...examining the use of DREADDs (Designer Receptors Exclusively Activated By Designer Drugs) to determine the ...to their Biosafety Level-2 or 2+. Please Note: Despite the fact that AAVs themselves are not pathogenic... CNS tropism (4). If axonal transport is not desirable, transport can be reduced by injecting a smaller...miRNAs), short hairpin RNAs (shRNAs), antisense oligonucleotides (ASOs), zinc finger nucleases, and many others...
  15. CRISPR Methods for Bacteria: Genome Engineering, CRISPRa, CRISPRi, Base Editing, and More

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    Blog Post
    ...Marraffini’s lab took advantage of this lethality to design the first synthetic bacterial CRISPR system in ...gRNA cassette for plasmid curing through "self-destruction" after induction with L-rhamnose and aTet. CRMAGE...citrea scarless editing plasmids Sheng Yang’s lab describes a two-plasmid system that combines recombineering...Streptomyces (Cobb et al., 2015). pCRISPomyces-1 includes Cas9, a tracrRNA, and a CRISPR array, while pCRISPomyces...editing efficiency, perhaps due to its condensed design. For both systems, custom spacers/gRNAs are easily...et al., 2013), the Qi lab employed a gRNA-based design more familiar to those using CRISPR in eukaryotes...plasmid tools that can be used in this way. As described in the above CRISPRi section, the Marraffini Lab...
  16. CRISPR Activators: A Comparison Between dCas9-VP64, SAM, SunTag, VPR, and More!

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    Blog Post
    ...that requires modest gene activation. Synergistic Activation Mediator (SAM) Description SAM uses specially...-component system dependent on gRNA design (SAM) or peptide design (SunTag). This streamlines its delivery...genes across diverse cell lines.   dCas9-VP64 Description CRISPR activation can occur through fusing dCas9...requires a relatively simple construct, it exhibits modest levels of gene activation, with some genes experiencing...VPR and SunTag) (Chavez et al., 2016). SunTag Description Rather than using a single copy of VP64 per each...expressed consistently throughout cells. VPR Description VPR fuses a tripartite complex with dCas9 to ...
  17. Synthetic promoter AAVs for cell-type specific expression in retinal cells

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    Blog Post
    ...expression in the retina.  Four approaches for designing synthetic promoters  To build a library of synthetic...synthetic promoters, the Roska lab used four different design strategies: Strategy #1 (ProA): Create promoters...promoters with the help of epigenetic analysis and designed using stretches of DNA that were transcriptionally...mice. Figure 1: The four strategies used to design synthetic promoters. Legend: TSS: transcription...class of cells  Of the four different promoter designs, promoters from strategy #4 had the highest rate...here.  Applications for synthetic promoter AAVs Besides restricting AAV transgene expression to particular...research for gene therapy. The Roska lab hopes to design improved versions of their current promoters, as...
  18. Viral Vectors 101: Chemogenetics

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    Blog Post
    ...DREADDs DREADDs DREADDS, or designer receptors exclusively activated by designer drugs, are G protein-coupled...Relationship Studies for Designer Receptors Exclusively Activated by Designer Drugs. ACS Chemical Neuroscience...Chemogenetics has become a popular tool in the field as it provides a noninvasive method for manipulating cell activity...Roth's and Takafumi Minamimoto's lab called deschloroclozapine (DCZ) shows promise as a CNO alternative ... Gomez J, Ramirez M, Hu X, Galvan A, Basu J, Michaelides M, Sternson S (2019) Ultrapotent chemogenetics...Conditional expression and signaling of a specifically designed Gi-coupled receptor in transgenic mice. Nature...
  19. Mobile-CRISPRi: Bringing CRISPRi to Diverse Bacteria

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    Blog Post
    ... human gut flora. Guides targeted essential and non-essential genes with two guides per gene. The library...expressing guides that target essential genes were less represented while bacteria containing guides targeting... Jason Peters, Oren Rosenberg, and Carol Gross provides a streamlined suite of tools for using CRISPRi...existing bacterial CRISPRi methods. First, its modular design allows for customization with strain-specific promoters...s take a look at the essential gene folA which encodes the target for the antibiotic trimethoprim. When... modular nature allows for the customization of guides, promoters, selection markers, and different versions...
  20. Don’t FRET: Bimolecular Fluorescence Complementation Makes Visualizing Protein-Protein Interactions Easy

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    Blog Post
    ...This post was contributed by Patrick Miller-Rhodes from the University of Rochester Medical Center.  ...plasmids for your experiment at Addgene! How to Design a BiFC Experiment Much like FRET, BiFC experiments...quantification (Kerppola, 2006, 2013). These are described in more detail below: Fusion protein construction...each PIP and empirically test which combination provides the best fluorescent signal. As for linker sequences...single FP. Your control construct may generate a modest level of fluorescence due to the random association...lentiviral expression. For more detail on how to design BiFC experiments, detailed troubleshooting tips...Many thanks to our guest blogger Patrick Miller-Rhodes from the University of Rochester Medical Center...
Showing: 221 - 240 of 985 results