Skip to main content

We narrowed to 1,054 results for: tra

Showing: 361 - 380 of 1054 results
  1. DNA Purification Without a Kit

    Type
    Blog Post
    ... milk going to help me extract DNA from agarose gel?!”   The DNA gel extraction with glass milk method...re-used, but trace contamination could interfere with interpreting the results of transfection assays. Go... a similar workflow as a column-based plasmid extraction kit. First, you lyse the bacteria and denature...contamination and you can use a phenol chloroform extraction to remove remaining proteins and RNase. Finally...ready for use! Plasmid purification and DNA gel extraction with glass syringe filters Starting material:...fragments The plasmid purification and DNA gel extraction method described in Kim and Morrison is nearly...silica or glass, but the addition of a high concentration of a chaotropic salt (guanidine hydrochloride...
  2. New Optimized Genome-wide CRISPRko, CRISPRi, and CRISPRa Libraries

    Type
    Blog Post
    ...than depletion. Multiple strategies have been developed to recruit transcriptional machinery to dCas9 and...recruit additional transcription factors. The Root and Doench labs utilized tracrRNAs with two PP7 stem...additional transcription factors to the targeted region (Sanson et al., 2018) . This tracrRNA was combined... PubMed Central PMCID: MC4253859.  4. Konermann, Silvana, et al. "Genome-scale transcriptional activation...Cas9 derivatives. Unmodified Cas9 causes double stranded DNA breaks that commonly result in a complete ... domain, such as KRAB, to prevent efficient transcription from sgRNA targets. CRISPRi is effective in ...in a narrow range around the transcription start site (TSS). The Root and Doench lab selected sgRNAs in...
  3. Hot Plasmids - June 2019 - Optogenetics, Acoustic Reporter Genes, microRNAs, and the CRISPR-Cas9 system CHIME

    Type
    Blog Post
    ...synaptic transmission. Cleavage of VAMP2 renders it inactive, thus inhibiting neurotransmitter release....depositors demonstrated the utility of light-mediated suppression of synaptic transmission in brain slices... proteins scatter sound waves and create ultrasound contrast. At a very low volumetric density and with...vivo using ultrasound in Escherichia coli and Salmonella Typhimurium. This work demonstrates engineered...Plasmids podcast Light-mediated block of synaptic transmission Article contributed by Klaus Wanisch  Listen...enable VAMP2 cleavage, and suppresses neuronal transmission within minutes. Constructs using the photodimerizer...other vital systems in the body. When a microbe travels through a host organism, the expression of some...
  4. Viral Vectors 101: Inverted Terminal Repeats

    Type
    Blog Post
    ...containing transcription factor binding sites can increase transgene expression and transduction efficiency...as the gene that they package. In a transfer plasmid, the transgene is flanked by two ITRs, and the ITRs...vectors, modifications can affect gene transfer efficiency and transgene expression (Zhou et al. 2017). For...these mutations can affect transduction efficiency and subsequent transgene expression. Replacing the ...nucleotide sequences that flank the ends of the single stranded DNA genome of AAV in the native virus. Since the... reduce the packaging efficiency but increase transgene expression (Zhou et al., 2017). The most common...efficiency (Shitik et al. 2023). Transgene expression can be altered by using ITR sequences from different AAV...
  5. Advanced Uses of Cre-lox and Flp-FRT - A Neuroscientist’s View

    Type
    Blog Post
    ...mcherry) are used in high concentrations in combination with low concentrations of vectors expressing the...recombinase. The high concentration of FLEx vectors guarantees that most cells are transfected with all labeling...7624356. PubMed Central PMCID: PMC41457. 8. Schnütgen, Frank et al. 2003. “A Directional Strategy for Monitoring... sites can lead to excision, inversion, and translocation of DNA in a similar fashion as between loxP ...-LDB domains of the fusions allowing Cre/FLP translocate to the nucleus where they exert their recombinase...brain? Cells of a specific brain area can be transfected by in utero electroporation. To achieve sparse... could reduce the plasmids amounts to reduce transfection efficiency. However, if the cellular structure...
  6. Harnessing TnpB for Genome Editing: A Compact and Versatile Tool for Your Research

    Type
    Blog Post
    ...Importantly, they allow transient delivery, enabling transgene-free genome editing (no transgene integration), ..." (one for each strand), while TnpB, like Cas12a, uses just one to cleave both strands. Similar to how... by Dr. Kutubuddin Molla, investigator at ICAR-Central National Rice Research Institute. When it comes...also need a short sequence motif called a TAM (transposon-associated motif), which is positioned like Cas12a...parts: a structural scaffold derived from the transposon's right-end element, and a 20-nucleotide (nt) ...downstream of the TAM, creating staggered double-strand breaks like those created by Cas12a. Applications...smaller than Cas9 alone. In our recent study, we demonstrated that TnpB can also function as an efficient ...
  7. Troubleshooting Your Plasmid Cloning Experiment

    Type
    Blog Post
    ...to the strategy adopted, and to the specific reaction you are running. Transformation Transform a few ... them an E. coli  strain known to be sensitive to that antibiotic, and if the strain is growing fine, ... positive clone, try transforming the ligation mix in different bacterial strains (stbl2, NEB stable, ...The PCR could fail to produce a product, the transformation may not result in any cells, or all the colonies... will definitely help in understanding if your strategy will be successful, and to avoid easy mistakes...combination of different ways according to your cloning strategy: Restriction enzyme digestion Be mindful of the...faster cloning. Remember to quantify the DNA concentration of all the samples by gel or by nanodrop to ...
  8. Plasmid Tools for Microbiome Studies

    Type
    Blog Post
    ..., the ability to detect mRNA transcripts of toxins and other transcripts of interest is a benefit of this...Microbiome studies have traditionally fallen into studies of who’s there and what are they doing. To ...the organisms present while sequencing of all transcripts gives clues into what the microbes are doing.... scientists introduce an Escherichia coli donor strain into the microbiome to deliver a genetic payload... microbial species. These also contain the RP4 transfer origin as well as a selectable marker and a desired...followed by a reporter gene. The hairpin blocks translation by sequestering the RBS, but binding of the “...microbial community) reveals the RBS and allows translation of the reporter gene resulting in GFP signal....
  9. Pairing CombiGEM and CRISPR for Combinatorial Genetic Screening

    Type
    Blog Post
    ...PubMed PMID: 25307932. PubMed Central PMCID: PMC4253859. 4. Hart, Traver, et al. "High-Resolution CRISPR...CombiGEM uses iterative one-pot reactions with straightforward restriction digestion and ligation steps to... in each plasmid. Each gRNA combination can be tracked and quantitatively analyzed by sequencing its set...expression of other genetic elements including transcription factors (Cheng et al., 2014) and microRNAs (...including those found at Addgene! Figure 1: Strategy for assembling the barcoded gRNA library pool....before beginning your experiments. Figure 2: Strategy for assembling barcoded combinatorial gRNA libraries...2014): 12462-12467. PubMed PMID: 25114216. PubMed Central PMCID: PMC4151723. 2. Doench, John G., et al. "...
  10. Plasmids 101: Cre-lox

    Type
    Blog Post
    ...allowing the four Cre proteins to form a tetramer. A double-strand DNA break occurs within the core spacer...maintained).  Translocation: If the sites are on separate DNA molecules, a translocation event is generated... expression – placing a series of transcriptional and translational termination features with loxP sites...2839833. PubMed Central PMCID: PMC281709. 3. Tissue– and site–specific recombination in transgenic mice. Orban... pun) specific, targeted DNA modifications in transgenic animals, embryonic stem cells, and/or tissue-...recombinase”), is a 38 kDa protein responsible for intra- and inter-molecular recombination at the loxP recognition...spacer of each loxP site and the two strands are ligated, resulting in the reciprocal crossover event. This...
  11. Selecting Your Plasmid Purification Kit

    Type
    Blog Post
    ...BioRender.com. Transformation Grade DNA (low quality/low quantity) – Bacterial transformation protocols require...eluting the DNA from the substrate. In a column-based approach, the substrate is a silica matrix fixed... large amounts of high quality DNA. Figure 1 illustrates the three grades of DNA you may need based on...highest-competency cells you will still struggle to get transformants if the plasmid you are using is completely degraded...important reactions like PCR or restriction digests. Transfection Grade DNA (high quality/high quantity) – Depending...Depending on the experiment, mammalian cell transfections can require quite large amounts of DNA (easily...the plasmid DNA from your cleared lysate to a substrate, washing away left-over debris that carried over...
  12. CRISPR Activators: A Comparison Between dCas9-VP64, SAM, SunTag, VPR, and More!

    Type
    Blog Post
    ... a strong transcriptional activation domain. Guided by dCas9, VP64 recruits transcriptional machinery ...as two other potent transcriptional activators (p65 and Rta). These transcriptional activators work in ...interest. Upon binding, CRISPRa systems recruit transcription factors to increase gene expression. CRISPRa...CRISPRa methods vary in their transcriptional activators: some methods rely on fusion proteins while others...gene regulation. This can be used to activate transcription during either initiation or elongation, depending...uses specially engineered sgRNAs to increase transcription. This is done through creating a dCas9/VP64 ...at each loci of interest, this allows more transcriptional machinery to be recruited per targeted gene...
  13. CRISPR 101: Targeting Non-Coding RNAs with CRISPR/Cas9

    Type
    Blog Post
    ...signal downstream of the transcription start site will terminate transcription of most of the ncRNA (Figure... schematic illustration of CRISPR/Cas9-based approaches to study ncRNAs. (A) Transcription start site ... coming, right? Non-coding RNAs (ncRNAs) are transcribed but do not encode proteins. They play important...Using a single guide RNA (sgRNA) to create a double-strand break works well because very small deletions and...sequence can completely disrupt expression of the transcribed ncRNA (Jiang et al. 2014).  Simple knock-out ...lncRNA regulatory elements that are crucial for transcription and downstream function. Rather than attempting...the lncRNA locus, scientists can mutate the transcription start site, splice sites, exons, and/or promoters...
  14. Hot Biosensors 2022: Year-End Roundup

    Type
    Blog Post
    ...Modular fluorescence unit fused with TRansmembrane region-to-IntrAcellular loop linkers” (MTRIA for short),...-gTEMP plasmids here!   Lu K, et al. Intracellular Heat Transfer and Thermal Property Revealed by Kilohertz...new class of sensors for neuropeptides and neurotransmitters. Motivated to develop a biosensor for oxytocin...sensors based on GPCRs recognizing various neurotransmitters, neuropeptides and other ligands - almost ...inserting a circularly-permuted GFP into an intracellular loop of various G-protein-coupled receptors....fluorescent sensor for real-time measurement of extracellular oxytocin dynamics in the brain. Nat Methods....kinetics and localization for imaging synaptic transmission. bioRxiv 2022.02.13.480251. doi: 10.1101/2022.02.13.480251...
  15. Antibodies 101: Beyond Surface Labeling

    Type
    Blog Post
    ...found in the extracellular space. The targeted epitopes can be motifs within transmembrane proteins, such...nature, antibodies cannot penetrate the cell membrane; hence, intracellular labeling with antibodies requires...label intranuclear proteins of interest, you can label cytosolic proteins alongside the intranuclear ones...such as receptors, or post-translational modifications on those proteins, like glycosylation patterns....cells. However, there are more techniques and strategies one can employ beyond simply incubating cells...downstream applications, like an in vivo adoptive transfer of those CD8+ T cells, require the cells to be...your sorted cell sample than MACS. An effective strategy to sort out your cells of interest via FACS using...
  16. Fluorescent Proteins 101: When GFP lets you down

    Type
    Blog Post
    ...18930153. PubMed Central PMCID: PMC2644460. 12. Querido, Emmanuelle, and Pascal Chartrand. "Using fluorescent...folded beta-barrel structure, followed by an intramolecular reaction that generates the chromophore (Tsien...and require uptake by the cells. Which of these strategies works best for a specific biological system under...intensity of purified protein at different acid concentrations. Overviews of the pKa values of different fluorescent... tag and several others. Another peptide-based strategy uses an enzyme to covalently label the peptide...specific RNA stem loop-structure (Querido and Chartrand, 2008). Finally, a nuclease-deficient Cas9 can... Since longer wavelengths have better tissue penetration, (infra)red fluorescent proteins are also a better...
  17. Adeno-associated Viruses (AAVs) for Genome Editing

    Type
    Blog Post
    ...is composed of single stranded DNA, which is particularly well suited for strand invasion, a key step ... are then packaged into AAV virions via transient transfection of 293T cells with helpers, and used to...identical targeting vectors delivered through transfection of naked DNA. Other investigators who had been...inserted downstream of a functional promoter (gene traps). The resultant gene targeting system could be used...the efficiency of homologous integration via gene trap enrichment, whereas pAAV-TK-Acceptor has a conventional...specific frameshift mutations through aberrant double strand break repair, it has proven more challenging to...AAV-based gene editing via the introduction of a double strand break by using a targeted nuclease. Asuri et al...
  18. Multiple Plasmids at a Low Price: Kits from Addgene

    Type
    Blog Post
    ...genes from a single transcript, or if you want to prevent read-thru transcription from resulting in the...developing a general translation initiation sequence known as the Species-Independent Translational Sequence (SITS...extensive sequences used for cloning into the final translated products. Negative selection markers built into...3509-3514. Tikhonova, Elena B., et al. "A transcription blocker isolated from a designed repeat protein...of which you can clone your gene of interest. Translation of the standardized leader peptide prevents secondary...encoding your gene of interest from affecting its translation initiation and instead makes initiation heavily...the production of a downstream peptide, the transcription terminators in this series are just the tool...
  19. Evolution of Lab Techniques

    Type
    Blog Post
    ...techniques used to generate transgenic mouse lines, such as BAC transgenic or traditional knockins/knockouts, ...researchers generating transgenic animals may choose Southern blotting to screen founder transgenic animals for ...fragmented into smaller pieces, run on a gel, and transferred to a membrane for analysis through hybridization...for the inserted transgene because Southern blots have a lower false positive rate than real-time PCR (4...hydroxyl group required for the extension of a DNA strand (8). Adding a small amount of a single radiolabelled...regular nucleotides results in the synthesis of DNA strands of all possible lengths because extension is terminated...prevails. Sequencing whole genomes or profiling transcriptomes (RNAseq) require sequencing of many samples...
  20. Targeting HIV-1 with CRISPR: Shock and Kill or Cut it Out?

    Type
    Blog Post
    ...’s lab at Temple University has demonstrated two potential strategies for CRISPR-HIV therapeutics - one...one using dCas9-SAM to activate HIV-1 transcription and destroy infected cells, the other using wild-type... no viral protein. To solve this problem, two strategies have been proposed. The first, “shock and kill...cytotoxicity or the immune response. The second strategy is the simple removal of the HIV-1 genome from...histone deacetylase (HDAC) inhibitors to increase transcription of the integrated HIV-1 genome. For a targeted...dCas9-VP64 fusion commonly used to activate transcription, but with two additional activation domains ...domains (MS2 and p65) to enhance transcriptional activation. Zhang et al. designed multiple gRNAs to target ...
Showing: 361 - 380 of 1054 results