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  1. Generating Mouse Models Using CRISPR/Cas9

    Type
    Blog Post
    ...always guaranteed. To learn more about this process check out our Mouse Modeling blog posts: Part 1: Genetically...that better human health.     References Cong L, Ran FA, Cox D, Lin S, Barretto R, Habib N, Hsu PD, Wu...Last updated on Oct 1, 2020 by Aliyah Weinstein. This post was contributed by guest bloggers, Wenning...3.4% of founders establishing germline transmission of the transgene, this technique is still in need of ...and chimeric adults mated to produce completely transgenic offspring. Although powerful, this technology...the Cas9 endonuclease that creates the DNA double-strand break (DSB) at the target site, and a donor oligonucleotide...
  2. Plasmids 101: The protein expression toolbox

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    Blog Post
    ...blog! Fig. 1 CRISPR activator and repressor mechanisms Want to transiently induce expression..., they can deplete endogenous protein levels for 1-3 days. There’s also a CRISPR for that! CRISPR interference...small, double stranded RNA molecules that degrade target mRNA transcripts. When transiently introduced, ...fused to a transcriptional repressor to your gene of interest. It will inhibit transcription instead of...of introducing a DNA double strand break. Transient introduction of CRISPRi or inducible expression (more...LoxP vector.   Turn it off for a little while Transient suppression of expression is faster and easier...expression. Addgene has a dCas9 KRAB plasmid for transient knockouts!  Turn it on Turn it on forever Permanently...
  3. Plasmids 101: Sequence and Ligation Independent Cloning (SLIC)

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    Blog Post
    ...effective with as little as 3 ng of DNA!) Figure 1: Schematic of SLIC. To start the SLIC cloning process...Methods Mol Biol. 2012;852:51-9. doi: 10.1007/978-1-61779-564-0_5. PubMed. JBEI-J5’s guide to SLIC Resources...through transformation, so the cloned vector must be ligated. But in LIC, longer single-stranded overhangs...T4 polymerase (left branch); by annealing two separate PCR products (middle branch); or by incomplete ...step to retain products with single-stranded overhangs (right branch). The mixed PCR and incomplete PCR...overlapping regions of single-stranded DNA. But as long as the double-stranded region is long enough to hold...nicks easily repairable by the bacteria after transformation. LIC is a reliable cloning method, but it is...
  4. FlipGFP, a novel fluorescence protease reporter to study apoptosis

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    Blog Post
    ...contains 11 β-strands and one central ɑ-helix that can be split into 3 parts: (1) β-strands 1-9 (β1-9) and...and the one ɑ-helix, (2) β-strand 10 (β10), and (3) β-strand 11 (β11). Each part contains components and...developed, such as the Forster resonance energy transfer (FRET)-based executioner caspase reporters. In...need a protease reporter that has a large dynamic range and high brightness. The Shu Lab from UCSF designed...However, the lab wanted to increase the fluorescence range to better study the spatio-temporal dynamics of ...GFP (GFP1-9 and GFP10-11) by flipping a single β-strand of GFP, hence the name FlipGFP. FlipGFP increases...from β1-9 they will rapidly recombine with β1-9 strands nearby resulting in fluorescence within tens of...
  5. Viral Vectors 101: Viral Applications

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    Blog Post
    ...several advantages over traditional vaccines, including 1) cellular responses in addition to antibody response...and immunogenicity of attenuated, nef-deleted HIV-1 strains in vivo. Retrovirology. 2007 Sep 23;4:66. ...attractive due to the ease of transduction in difficult-to-transfect cell types ranging from primary to embryonic... traditional transfection and random genomic integration of a plasmid. Viral transduction is also generally...integrated into the genome of the target cell or transiently expressed. It’s important to note that for all...vector can express your construct in target cells transiently or constitutively depending on the virus used...generally less toxic to cells than transfections, preserving cell viability. Library delivery Screening...
  6. Hot Plasmids - May 2022

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    Blog Post
    ... et al., 2021).    Fig. 1: Schematic showing the workflow for the BLITZ system. Image from Xiong...Biol. 2022. https://doi.org/10.1038/s41556-021-00836-1 Visual barcodes for live cell clonal multiplexing...use of pre-existing transgenic lines, termed BLITZ (Biotin Labeling In Transgenic Zebrafish) (Xiong, et...“single-use” transgenic lines. Instead, researchers can generate and maintain transgenic lines that can...protein by a specific transcription response element (TRE) or kinase translocation reporters (KTRs). Find...interest and, for in vivo work, generate a dedicated transgenic line. Using zebrafish as a model organism, the...protein can then be co-expressed in essentially any transgenic zebrafish line expressing a GFP-tagged version...
  7. Viral Vectors 101: Biosensors

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    Blog Post
    ...Introduction to Biosensors. Essays Biochem. 2016 Jun 30;60(1):1-8. DOI: 10.1042/EBC20150001 Leopold, A. V., Shcherbakova... engineered to detect a wide array of neurotransmitters ranging from dopamine to glutamate, all the way... or animal system. This ‘thing’ could be a neurotransmitter, such as norepinephrine, or an electrolyte...last component of the biosensor is the signal transducer which will quantitatively give a readout for ...bio-recognition event is (fluorescence, pH, etc.). The transducer will generate a numerical value which represents...activated GFP expression (receptor), then the transducer could be a microscope, plate reader, or any other...—keep reading to find out how!   Neurotransmitters Many canonical fluorescent as well as FRET-based...
  8. A Practical Approach to Choosing the B(right)est Fluorescent Protein

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    Blog Post
    ... and, if you do it right, can be (part of) figure 1 of your next paper or thesis. This series of posts...An explanation of the assay is depicted in figure 1. The strict correlation between the fluorescent protein...brightness When a dish of mammalian cells is transiently transfected with a plasmid containing a fluorescent...fluorescent proteins, e.g. see Chudakov et al (2010), Cranfill et al (2016) or Thorn (2017). However, the theoretical...developed in our lab uses a reference protein that is translated from the same open-reading frame and separated...reference protein) under identical conditions, a ranking of the practical brightness can be made (Goedhart...repeating this with another fluorescent protein, a ranking of practical brightness can be made. This strategy...
  9. Back to Bacteria: CRISPR gRNA Multiplexing Using tRNAs

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    Blog Post
    ...modified slightly with either a 1-7 base poly(U)tail in tRNA-gRNA constructs or a 1-4 base tail from the second...tRNAs contain internal transcriptional elements that enhance pol III transcription, potentially increasing...base Csy4 recognition sites from a polycistronic transcript. Although this method shortens construct size...coexpression of Csy4 with Cas9 and the polycistronic transcript. As nucleases may have off-target effects and...matching traditional gRNA-expressing constructs, transcript levels of PTG1 and PTG2 were 3 and 31 times higher... of polycistronic gene organization, and its translation to CRISPR/Cas9 shows great potential for multiplexed...
  10. Sweating the Small Stuff: Details in the Lab

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    Blog Post
    ... to focus, which was extremely effective. Others ran experiments at odd hours, used more secluded workspaces...consistently and accurately run a protocol.   Figure 1: Evolution of a Western blot protocol, from a full...
  11. How to Design Your gRNA for CRISPR Genome Editing

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    Blog Post
    ...non-functional allele. For a 1 kilobase gene, since potential target sites occur ~1 in every 8 nucleotides,...10.1038/s41576-018-0059-1 Veres A, Gosis BS, Ding Q, Collins R, Ragavendran A, Brand H, Erdin S, Cowan CA... efficacious to target the coding or non-coding strand of DNA. As a rule of thumb, we avoid target sites..., 2020). is not limited to single nucleotide transitions but still requires a nearby PAM, although these... modulating gene expression at the level of transcription – CRISPRa (activation) and CRISPRi (inhibition...most-efficacious to target a ~100nt window upstream of the transcription start site (TSS), while for CRISPRi, a ~100nt...of producing the guide (synthetic, in vitro transcription, or lentiviral delivery) can affect the accuracy...
  12. Troubleshooting Your Plasmid Cloning Experiment

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    Blog Post
    ...are working with is correct. It's also best to use 1-2 ug of the vector for digestion. PCR Design primers...plasmid; a starting point could be a molar ratio of 1:2 (plasmid:insert), but this parameter has to be optimized...the specific reaction you are running. Transformation Transform a few microliters of your ligation reaction...The PCR could fail to produce a product, the transformation may not result in any cells, or all the colonies...fragments If you don’t get any positive clone, try transforming the ligation mix in different bacterial strains...
  13. Deep Dive: Statistical Tests (Comparisons)

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    Blog Post
    ...method entails arranging all calculated p values from smallest to largest and ranking them (1 being the smallest...error, variance, data ranges. how closely data points fall to each other (see Fig. 1). Alpha values –...statistical test assumes your data follows. Fig. 1: Examples of comparable groups with and without equal...significance by finding the largest p value where its rank divided by the total number of comparisons performed...– Tukey’s test, Newman-Keuls, Duncan’s multiple range test, and several others. Each test has different...negatives, moderate false positives. Duncan’s multiple range test – Most powerful. Low false negatives, high ...): 126-130 (2012). 10.1097/SMJ.0b013e3182498ad5 Curran-Everett, Douglas. Explorations in statistics: statistical...
  14. Suggest A Plasmid You'd Like to Find at Addgene

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    Blog Post
    ...to reach out to potential depositors in two ways: 1. Fill out our "Suggest a Plasmid" form Fill out the...where we can find the plasmid. While we cannot guarantee that everyone we reach out to will end up depositing...
  15. Choosing the B(right)est Fluorescent Protein: Aggregation Tendency

    Type
    Blog Post
    ...protein of interest will be problem-free. In figure 1 we provide an example of the OSER assay with a number...can be shared by publishing it as (part of) figure 1, uploading it as a preprint, or documenting it in ...not by Cranfill et al (2016)). Moreover, good performance in the OSER assay is not a guarantee that using...fluorescent proteins when protein tagging is the goal (Cranfill et al, 2016; Constantini et al, 2012). The localization...
  16. Predicting Adverse Reactions to Monoclonal Antibody Drugs

    Type
    Blog Post
    ...immunogenicity score (Mattei et.al., 2022).    Figure 1: Generation of immunogenicity scores by predictive...antibodies for the treatment of diseases. J Biomed Sci 27, 1 (2020). https://doi.org/10.1186/s12929-019-0592-z  ...ADAs can inactivate the drug and increase drug clearance, lowering its efficacy and increasing the risk...
  17. Antibodies 101: Stripping and Reprobing Western Blots

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    Blog Post
    ...Glycine-HCl 25–200 mM SDS 0.1%–1% (w/v) Tween 20 (optional) 1% (v/v) HCl Adjust to pH 2.0... your gel and membrane transfer as normal. Immediately after transfer, dry the membrane to maximize protein...you from having to run a whole new gel and membrane transfer. Let’s get started! Before you begin In the...manufacturer’s instructions for the membrane you are using. Dry nitrocellulose membranes are brittle, so proceed ... as normal! Stripping your membrane Alright, so you’ve dried your membrane and returned it to buffer, ...’ll want to: Rinse the membrane in water or fresh buffer. Cover the membrane in stripping solution and...a fume hood. Rinse the membrane in water or fresh buffer. Cover the membrane in stripping solution and...
  18. New Tool for Lineage Tracing: The ClonTracer Library

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    Blog Post
    ... of two outcomes (see schematic depiction below): 1. Resistant cells among the separate replicates would...development of combination therapies.         References 1. Hyo-eun, C. Bhang, et al. "Studying clonal dynamics...library was developed when Carrie was a post-doc in Frank Stegmeier’s lab in Novartis Oncology.  Bhang did...lentiviral vectors with roughly 73 million semi-random, 30 bp DNA barcodes that are integrated into target...
  19. CRISPR 101: Cas9 vs. The Other Cas(s)

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    Blog Post
    ...none. Best for: targeting single stranded RNA.   Table 1: Fast facts on Cas family proteins...The main differences between Cas7-11 and Cas13 are 1). non-specific RNA cleavage and 2). cell toxicity.... it will proceed to generate a blunt DNA double strand break. Cas9 has been studied for genome engineering...an expanding number of others. Best for: a wide range of DNA edits.   Cas3 – The shredder What sets Cas3...locates its target sequence and initiates single stranded DNA degradation. Cas3 DNA digestion can proceed...convenient for targeting experiments requiring single strand DNA generation, such as homology directed-repair...therapeutic delivery.   Cas14 – Mini, but single strand mighty Unlike many other Cas enzymes, Cas14 targets...
Showing: 401 - 420 of 711 results