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  1. Plasmids 101: Colony PCR

    Type
    Blog Post
    ...step to colony PCR is designing primers. There are 3 strategies for primer design: 1) insert-specific primers... second option is to design backbone-specific primers. These primers are designed to anneal to sites that...less money. The key steps to colony PCR are: 1) design primers to detect the presence of your insert; ...things to consider when performing colony PCR.   Designing colony PCR primers The first and perhaps most ...-specific primers: Insert-specific primers are designed to anneal to an insert-specific sequence. This...backbone but that contain different inserts. When you design primers to anneal outside the cloning site, it ...about insert orientation, then you might consider designing orientation-specific primers. Blunt end cloning...
  2. CRISPR Challenges: Standardization and Homology Directed Repair

    Type
    Blog Post
    ...working with CRISPR than just designing a repair template that contains your desired edit, and I want to make...say about CRISPOR, a tool to help you design, pick, and close guides for Cas9 and Cpf1. This tool supports...The blog post I mentioned, John Doench’s How to Design your gRNA for CRISPR Genome Editing, gets over ...these numbers show that this basic concept of gRNA design is still challenging for researchers using CRISPR..., and that standardizing and improving the gRNA design process and rules for various applications is necessary...tackle the challenges of DNA repair (with bonus gRNA design resources.) Subscribe to CRISPR updates on our ...in Human Cells Hands-on tips for repair template design from guest bloggers Dominik Paquet and Dylan Kwart...
  3. Comparing Cas9 to NgAgo: Can the Argonautes Best CRISPR?

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    Blog Post
    ...DNA guides NgAgo uses 5’ phosphorylated DNA guides (so called “gDNAs”) rather than the RNA guides employed...24 base DNA guides may be more user-friendly, since they can be ordered as oligonucleotides and should ...gDNA guides will also need to be transfected into the cells of interest. In contrast, RNA guides must ...important role in RNA interference, binding RNA guides to cleave foreign RNA. Argonaute proteins are also...cleave DNA in vitro, directed by phosphorylated DNA guides. Unfortunately, Swarts et al. were unable to show...NgAgo preferred certain guide sequences - using 5 guides/gene for 10 genes, they did not observe differences...a different approach, randomly removing 1-20 nucleotides from the cleavage site specified by the gDNA....
  4. Rewiring Metabolic Circuitry with CRISPR RNA Scaffolds [Video]

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    Blog Post
    ...for CRISPRi are described here: http://www.addgene.org/crispr/qi/ Plasmids described in  Zalatan et ...stepwise protocol on designing and using RNA scaffolds: Delebecque, C. J. et al. Designing and using RNA scaffolds...regulators allows a greater degree of control of desired expression levels dependent upon the type of transcriptional...transcriptional regulator or the number of designed scaffold binding sites. With hundreds of characterized...tunability of transcription is possible. From a design perspective, this is appealing since the RNA scaffold...pairing, allowing for rational, straightforward design. Since the technique relies on base pairing, it...and multidirectional multiplex control via scRNA design is readily apparent in metabolic engineering. The...
  5. Twenty Years of Sharing: Expanding Accessibility

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    Blog Post
    ...shipping. However, there were issues that persisted despite our best efforts. With a little over half of our...packages navigated customs and arrived at their destination in a timely manner and at the correct temperature...for their experiment.     Table 1: Most popular guides, protocols, and collections of 2023. Educational...Educational Resource Top Five by Views Guides CRISPR Guide Lentiviral Guide AAV Guide Optogenetics...Electrophoresis Bacterial Transformation How to Design a Primer Creating Bacterial Glycerol Stocks Inoculating...Origin of Replication What is a Plasmid? How to Design Your gRNA for CRISPR Editing The Promoter Region...Analysis Videos What is a Plasmid? How to Design Primers for PCR Agarose Gel Electrophoresis Inoculating...
  6. Screening for Successful Genome Editing with Digital PCR

    Type
    Blog Post
    ...your genome edits, this paper provides detailed instructions on how to design such assays, in addition to...great deal of precision. This means digital PCR provides an absolute measure of target abundance, does ...what kind of assays can be used to sniff out your desired mutations. The assays you will use aren’t that ...often used in real time PCR. These assays can be designed to detect either a donor sequence integrated through...non-homologous end joining (NHEJ) (2-5), depending on your desired genome edit. Since exploitation of NHEJ to generate...the target locus, as well as a reference probe designed to bind at an unedited site distal tothe predicted...double strand break, and a NHEJ/ “drop-off” probe designed to bind directly at the predicted double strand...
  7. Kiran Musunuru on the Newest TALEN Genome-Editing System

    Type
    Blog Post
    ...essentially any DNA sequence desired. This technology allows you to create a pair of designer proteins that will...nucleases that will bind desired sequences. TALENs are much more reliable. If you design them for a particular... simple to design TALENs. It only takes two to three days from the moment you are designing a TALEN on...Cell, Musunuru, Chad Cowan and their colleagues describe a much more efficient tool for doing that disease...people unfamiliar with this new TALEN kit, can you describe it for us? Musunuru: TALENs are a type of genome...target a particular DNA sequence? Musunuru: The kit includes 832 plasmids containing prefabricated pieces that...to build a DNA-binding domain to recognize any desired 15 base pair sequence in the genome in rapid fashion...
  8. CRISPR 101: Validating Your Genome Edit

    Type
    Blog Post
    ...screening by PCR may be the way to go. Design a PCR to flank your desired edit site and run the PCR product...nucleotide along with your desired edit. This silent mutation should be designed solely for restriction enzyme... updated Nov 3, 2022 by Susanna Stroik. You’ve designed your gRNA and introduced it into your target cells... your cells were appropriately edited for your desired mutation - insertion, deletion, or site-directed...know a few things about your target cells and the desired edits. First, you will need to know what the ploidy...knockout mutations When a knockout cell line is desired, any mutation that introduces a frameshift in the...frequency of your sgRNA-Cas9 combo. Pro tip: When designing your PCR, ensure there is at least ~200 base pairs...
  9. Plasmids for Endogenous Gene Tagging in Human Cells

    Type
    Blog Post
    ... later this year. Designing the donor plasmid Figure 2: Donor plasmid design strategy. A donor ...with each cell line. The editing strategy and design described above can be used to create similar donor ...GFP tag and 1kb of homologous DNA flanking both sides (about 2.7kb total)—is inserted into a plasmid backbone...plasmid to prevent the plasmid from being cut and destroyed by CRISPR/Cas9 during transfection. Making the...use electroporation, a technique that briefly destabilizes the cell’s outer membrane and allows the components...Addgene’s CRISPR-based Protein Tagging collection includes systems for tagging mammalian cell lines, Drosophila...
  10. Plasmids 101: Control Plasmids

    Type
    Blog Post
    ...and should be designed accordingly. If you are trying activate a gene, you should design a control that...carried out by scientists every day. Although the designs and outcomes may vary, one thing should be present...these control plasmids are critical for the correct design of the experiment.  The Experiment: Knockdown the...control plasmids Part of planning your experiment includes determining what factors need to be controlled...microscopy images resulting from our experiment that includes the aforementioned internal control and is consistent...correct interpretation of the results because it provides an important reference point when analyzing the...positive control, the internal control vector, was described earlier. Once you are sure your conditions are...
  11. Tetracycline Inducible Expression

    Type
    Collection
    ...tetracycline, tetracycline binds to tetR. This precludes tTA binding to the tetO sequences and subsequent...and induce your gene of interest. ID Plasmid Description Co-expressed tTA, rtTA, or TetR On or Off PI ...transactivator for your tetraycline system. ID Plasmid Description Element On or off PI 26429 pLenti CMV rtTA3 Blast...
  12. 3 Tips to Improve HDR Efficiency for CRISPR Editing in Human Cells

    Type
    Blog Post
    ...overall HDR rates, we have shown recently that desired genome-editing events by HDR can be generated more...genome editing with CRISPR/Cas9 in human cells was described in 2013 (Cong et al, Mai et al) we were very excited...introduced. Although we were able to introduce the desired mutations in genes associated with dementia, such...CRISPR from re-cutting the target sequence once the desired edit has been introduced. We found that blocking...only saw incorporation of the blocking mutation. Despite the fact that both the blocking mutation and our...thinking further about the distance relationship described above, we realized that, in addition to increasing...efficiency a guide RNA targeting a cut <10 bp from the desired mutation should be used. For a heterozygous event...
  13. Choosing the B(right)est Fluorescent Protein: Photostability

    Type
    Blog Post
    ...different ways. We describe a number of issues with some of the experimental designs used to make these...of Amsterdam. The previous post in this series described a practical approach to selecting a bright fluorescent... protein. Photobleaching is the irreversible destruction of a fluorophore under the influence of light...photobleach at some point. For live-cell imaging, it is desirable to have fluorescent proteins that are photostable...photoswitching (Kremers et al, 2009), which usually are undesired properties. In the ideal situation, a fluorescent...large number of emitted photons before they are destroyed. Factors that affect photostability The photobleaching...fluorescence, which, in its simplest form, can be described by a mono-exponential decay (analogous to radioactive...
  14. Fluorescent Tagging of Endogenous Genes with SapTrap

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    Blog Post
    ...SapTrap, the user first designs either oligos or synthetic DNA for the desired gRNA target sequence, as...specified by a guide RNA (gRNA) sequence. Users can design gRNAs to induce the break at a specific genomic...need for PCR or cloning, as digestion of the destination vector with SapI yields 2 sites- the first site...accepts the homology arm repair template. SapTrap includes a prebuilt donor plasmid library containing several... and a Cas9 expression plasmid will insert the desired genetic tag and marker sequence into the targeted... a tissue specific manner, as well as 3-site destination vectors for inserting a tag at multiple target... not work with C. elegans, several groups have designed modular toolkits to assist with tagging genomic...
  15. Evolution of Lab Techniques

    Type
    Blog Post
    ...the order of nucleotides in a string of DNA (7). Sanger sequencing uses modified nucleotides, called dideoxynucleotides...the widespread use of Sanger sequencing. Building upon this technology, radiolabelled nucleotides were...causes sickle cell anemia. The mutation happens to destroy a sequence recognized by the restriction enzyme...synthesis reaction along with all four regular nucleotides results in the synthesis of DNA strands of all...fluorescence activity as fluorescently labeled nucleotides are incorporated, a method called pyrosequencing...nanopore-based DNA sequencing which reads the nucleotides of a DNA strand as it slips through a tiny pore... the different electrochemical properties of nucleotides (8). Compared to older technologies nanopore-...
  16. A Needle in a Base-Stack: Cas9 Structural Biology

    Type
    Blog Post
    ...Have you ever designed a CRISPR guide RNA and wondered why it is limited to only 20 bases, or why it’...understand the parameters of CRISPR experimental design. Let’s dive into some structural biology! Major... lobes, REC and NUC, and their subdomains. NUC includes the HNH and RuvC catalytic domains, as well as...as the CTD (also known as the PI), while REC includes most of the bridge helix. Created with BioRender.com...Fact! Even though the Cas9:RNA complex is well described in the closed conformation, recent electron microscopy... does not include stem loop 3, and guide RNA nucleotides 11-20 are not resolved due to structural disorder...2017). Within an interior cavity, Cas9 grips nucleotides 1-10 of the guide RNA, prearranged for base pairing...
  17. Optogenetics AAV Preps

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    Collection
    ...ChrimsonR (soma-targeted) mRuby2 Cre dependent 9 Adesnik 124603 pAAV-EF1a-DIO-ChrimsonR-mRuby2-KV2.1-WPRE-SV40... ChroME (soma-targeted) mRuby3 Cre dependent 9 Adesnik 124651 pAAV-CamKIIa-ChrimsonR-mScarlet-KV2.1 CaMKII...eGtACR1 (soma-targeted) mRuby3 Cre dependent 9 Adesnik 137155 pAAV-nEF-Con/Fon-iC++-EYFP nEF iC++ EYFP...
  18. Deep Dive: qPCR

    Type
    Blog Post
    ...from Wong, 2018   Primers Design of primers and probes Primer design, of course, could easily be its...useful primer design resources in the References and Resource section. Validation Once designed, your primer.... For example, chemistries that rely on hairpin design of probes/primers often offer higher allelic specificity...Taqman) Low; can be reduced with a double-quencher design Yes, one Yes Yes Agarose gel or uMelt analysis...Reference Genes  Choosing a set of reference genes deserves more attention than it usually receives. Different... multiple reference genes whenever possible (Vandesompele, 2002), and it's possible to multiplex your ...documented in the literature, a geNorm study (Vandesompele, 2002) will help you select the appropriate ...
  19. CRISPR Between the Genes: How to Experiment with Enhancers and Epigenomics

    Type
    Blog Post
    ...this article, Quilt CTO Aneesh Karve, shows how to design experiments that work anywhere in the genome. Aneesh's...enhancers! This leads us to a three-step approach for designing an experiment to identify the critical NANOG binding...Find Enhancers that have NANOG binding sites 2. Design a CRISPR screen to target and disrupt the NANOG...anyone can find enhancers with Quilt. Seek and destroy enhancers with CRISPR Armed with the genome math...expression for NANOG enhancers, we’re ready for step 2: design a CRISPR screen to disrupt these enhancers. The...attenuated retrovirus in the same family as HIV. By design, our lentivirii are genetically programmed to CRISPR...Lentivirus from Addgene If you’re interested in designing your own CRISPR screens for enhancers, check out...
  20. Plasmids 101: Positive and Negative Selection for Plasmid Cloning

    Type
    Blog Post
    ...property by including ccdB on its destination plasmids. In the destination plasmid, the ccdB gene is flanked... rest do not grow. While there are many ways to design your positive selection strategy, here are a few...straightforward in cases where the inserted DNA includes an antibiotic resistance marker. After transformation...grow. However, often times, the plasmid backbone includes an antibiotic resistance cassette and you aren...backbone contains your gene of interest. Auxotrophy Besides antibiotic selection, you can select for a successful...prototrophy come into play during cloning if you’ve designed your experiment using an auxotrophic strain of...sites. To introduce a gene of interest into the destination plasmid, recombination sites must first be added...
Showing: 181 - 200 of 985 results