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Showing: 101 - 120 of 862 results
  1. Your Lentiviral Plasmid FAQs Answered

    Type
    Blog Post
    Published
    April 23, 2014, 1:08 p.m.
    ...considered. Q2: Can I use lentiviral transfer vectors for transient transfections? A2: Technically, yes. Will ...produced by co-transfecting three essential ingredients: the lentiviral packaging vector, a transfer vector including...specifically for transient expression (find some useful backbones here) or from viral transduction. While not...3rd-generation transfer vectors apart? A3: Addgene defines 2nd- or 3rd-generation transfer vectors based... Are transfer plasmids replication competent? What is SIN? A6: Most (if not all) Addgene transfer plasmids...enhancers and the transgene; such interactions can alter expression of not only the transgene but also that...which is rarely more than 30% of the transfer plasmid. Many transfer vectors are SIN. Packaging plasmid...
  2. Viral Vectors 101: AAV Variables That Matter

    Type
    Blog Post
    Published
    June 1, 2023, 1:15 p.m.
    ...., 2017), axonal transport  (Murlidharan et al., 2014), and postsynaptic transmission (Oh et al., 2020... S. (2013). Analysis of Transduction Efficiency, Tropism and Axonal Transport of AAV Serotypes 1, 2, 5... an Immune Response against the Tetracycline-Dependent Transactivator Correlates with Long-Term Doxycycline-Regulated...Doxycycline-Regulated Transgene Expression in Nonhuman Primates after Intramuscular Injection of Recombinant...adeno-associated viral vector-mediated transduction of the corticospinal tract: Comparison of four promoters. ...Specificity of gfaABC1D-Driven Transgene Expression in AAV-Mediated Gene Transfer. Molecular Therapy - Nucleic...great in a GABA neuron, for instance, may not transduce the adjacent norepinephrine neuron at all. There...
  3. Advancing Biology with Zebrafish: Genetic Tools for Developmental Studies and More

    Type
    Blog Post
    Published
    Aug. 13, 2019, 12:58 p.m.
    ...their straightforward husbandry and ability to produce abundant, externally fertilized, transparent progeny...per individual to maintain. Also in contrast to mice, the transparent zebrafish embryo develops outside ...mRNA inhibit its translation either by blocking initiation or splicing. (RNAi, in contrast, engages existing...et al., 2019). Generating zebrafish transgenics Creating transgenic organisms by introducing foreign DNA...different experimental conditions. Strategies for generating transgenic zebrafish are well established (...Mosimann, 2016). One common and robust strategy uses a transposon called Tol2 to randomly integrate foreign...lineage tracing Over a period of 24 hours, the externally fertilized zebrafish zygote transforms into an...
  4. Plasmids 101: Control Plasmids

    Type
    Blog Post
    Published
    April 9, 2015, 3:29 p.m.
    ...effects of the transfection itself (i.e., the vector used in transfection, transfection reagent, or transfection...experiments employ transfection, negative, positive, and replicate controls.  Transfection controls: empty...vector and internal control A transfection control measures transfection efficiency and enables observation... allows you to examine if the transfection reagents or the transfection process itself has any cytotoxic...Another type of transfection control is an internal control vector, which measures transfection efficiency....luciferase) that is either co-transfected with the test plasmid or transfected into a separate well of your...GFP-expressing Plasmid B, could demonstrate whether the cells were transfected successfully and expressing...
  5. Mobile-CRISPRi: Bringing CRISPRi to Diverse Bacteria

    Type
    Blog Post
    Published
    April 4, 2019, 12:53 p.m.
    ...species. Existing protocols can transfer CRISPRi into a single bacterial strain, such as a B. subtilis, or ...bacterial Tn7 transposon system. This system has two parts: a plasmid expressing the Tn7 transposition genes ...chromosomal copy of the RP4 transfer machinery mobilize these plasmids for transfer to recipient cells during...: A Tn7 transposon containing the CRISPRi components and a plasmid with the Tn7 transposition genes are...are transferred to a recipient bacteria strain of interest by tri-parental mating. Donor bacteria contain...disease. However, the rate of transfer was variable. They measured transfer rates by comparing the number... P. mirabilis, had only ~1 transfer per 1,000,000 colonies. Higher transfer rates are better suited for...
  6. Viral Vectors 101: The Retroviral Lifecycle

    Type
    Blog Post
    Published
    July 27, 2023, 1:15 p.m.
    ...most cases, interested in transferring genes to mammalian cells (i.e. transferring DNA), yet retroviruses...still direct the translation of proteins because they integrate this reverse-transcribed DNA into the host...genome and then use cell machinery for transcription and translation. Here, we will discuss several aspects...worthwhile to generalize the idea of “transduction” to mean any transfer of material from the virus to the...a turn of phrase — “pseudotransduction” — to describe the direct protein transfer of RT, which would actually...After uncoating, reverse transcription follows the release of the two strands of viral RNA and of the ...structural proteins expressed from a reverse-transcribed piece of DNA called a “provirus.” This DNA is...
  7. New Tools Enable CRISPRa for Neuroscience Applications

    Type
    Blog Post
    Published
    July 2, 2019, 12:51 p.m.
    ...engineered combinations of transcriptional activators to induce gene transcription at genomic sites targeted...p65-HSF1 transcriptional activator to each genome-bound dCas9 (see Figure 1a for the transgenic construct...different untranslated or coding regions. Typically, each gene isoform has a distinct transcriptional start...relatively straightforward to use CRISPRa to selectively target these different transcriptional start sites...distinct transcriptional start sites, all of which yield the same BDNF protein. To demonstrate the specificity...investigation. Co-transduction of primary rat neurons with dCas9-VPR and sgRNAs targeting either transcript variant...are often many more genetic strategies) and then consider whether traditional cDNA overexpression is suited...
  8. Viral Vectors 101: The AAV Retrograde Serotype

    Type
    Blog Post
    Published
    April 27, 2023, 1:15 p.m.
    ...information from a region (anterograde tracer, Fig. 1B). Tracers are typically delivered to a particular... either trace downstream from the soma (neuron cell body) toward the axon (anterograde tracer) or upstream...making them useful tracers, but finding a virus that works well for retrograde tracing can be difficult....naturally exhibit retrograde transport and can therefore perform retrograde tracing, but often at the cost ...expression.     AAV retrograde Unlike traditional dye-based neuronal tracing reagents, AAV particles require...not be transduced at all by this serotype. Nichole Beebe in Brett Schofield’s lab demonstrated that pathways...neurons! Neurons are really cool because they can transmit information, for example, from one of the 180 ...
  9. Viral Vectors 101: Integrase-Deficient Lentiviral Vectors

    Type
    Blog Post
    Published
    May 13, 2025, 1:15 p.m.
    ...Reverse transcription of the transgene occurs in the cytoplasm, then the resulting double-stranded DNA transgene... transgene is incorporated into a large complex of both viral and cellular proteins and trafficked to .... However, IDLV genomes are transcriptionally active, leading to transient expression of gene products...mutagenesis (Howe et al., 2008). 2. Transient expression of transgenes/shRNAs If you want your cells to ... for stable expression of the transgene. This makes IDLVs an attractive choice for certain types of clinical...quantitative PCR titration of vector DNA in samples harvested 24 hours post-transduction (Wanisch and Yáñez-Muñoz...They rely on a viral protein called reverse transcriptase to convert their RNA genomes into DNA to be ...
  10. CRISPR Methods for Bacteria: Genome Engineering, CRISPRa, CRISPRi, Base Editing, and More

    Type
    Blog Post
    Published
    Sept. 28, 2020, noon
    ...modify a given gene. CRISPR-tranposons By combining CRISPR editing and transposons, the Sternberg and Zhang...developed CRISPR-transposons. The Sternberg lab's system called INTEGRATE (Insertion of Transposable Elements ... CAST (CRISPR-associated Transposase) both enable gRNA-directed transposition. INTEGRATE consists of four...multi-spacer CRISPR array, CRISPR-transposons can be multiplexed. Transcriptional repression (CRISPRi) in bacteria...s lab demonstrated that a minimal, regulatable CRISPR system effectively silenced transcription of one...repressed or activated transcription of select genes in E. coli. Furthermore, to demonstrate wider applicability...proteins involved in the activation of transcription including transcription factors, phage proteins, and RNAP...
  11. Technologies Enabled by NanoLuc® Luciferase

    Type
    Blog Post
    Published
    Feb. 8, 2018, 12:17 p.m.
    ...resonance energy transfer (BRET). The fluor then emits light at a tissue-penetrating wavelength above ...and imaged after i.p. or i.v. administration of the furimazine substrate for NanoLuc luciferase. Both ...luminescence. Intracellular Calcium Sensor Yang, J. et al. (7) wished to trigger intracellular Ca++ release...imidazopyrazinone substrate. ACS Chem Biol 7, 1848-57. PubMed PMID: 22894855. PubMed Central PMCID: PMC3501149...cloning with labs around the world and had specific strategies and tactics for getting the plasmids he wanted...group as well as evolution of the coelenterzine substrate to the more stable yet brighter furimazine by ...can generate autofluorescence and have limited penetration due to absorption by tissues. To avoid absorbance...
  12. Mouse Modeling, Part 1: Genetically Engineered Mice

    Type
    Blog Post
    Published
    July 11, 2019, 1:26 p.m.
    ...editing techniques. Inbred and outbred strains Mouse strains used in research can fall under one of two.... Common inbred strains include C57BL/6, Balb/c, and 129. Conversely, outbred strains were originally ...genetically diverse gene pool. Outbred strains are strategically bred to maintain maximum genetic heterozygosity...population. Outbred strains of mice are useful for comparing dominant and recessive traits and their impact...inducible gene expression. Transgenic and knockin mice As the name suggests, transgenic and knockin mice contain...DNA randomly into the mouse genome. In contrast, knockin strains are generated via homologous recombination...and provides a way to track successfully engineered cells. Similar to transgenic mice, knockout mice are...
  13. Fluorescent Proteins 101: Photoactivatable Fluorescent Proteins

    Type
    Blog Post
    Published
    April 25, 2017, 2:30 p.m.
    ...PA-FPs come in 2 flavours- monomeric and tetrameric. Tetrameric PA-FPS are better for whole cell imaging...By generating PA-FPs fused to intracellular proteins, scientists can track single protein localization,...localization, turnover, and trafficking, as well as organelle trafficking and dynamics (fission, fusion, etc). For...PubMed Central PMCID:PMC4007248. 11.Hess, Samuel T., Thanu PK Girirajan, and Michael D. Mason. "Ultra-high... proteins that display unique changes in their spectral properties upon exposure to a specific wavelength... wtGFP normally contains a mixed population of neutral (protonated) and anionic (deprotonated) forms of...generates a chromophore population that is more neutral, causing PA-GFP to display almost no fluorescence...
  14. Plasmids 101: Codon usage bias

    Type
    Blog Post
    Published
    Sept. 27, 2018, 1:09 p.m.
    ...structures in RNA transcripts Effects on transcription (remember, it’s not all about translation - e.g. codon...codons encode single amino acids. Evolutionary constraints have molded which codons are used preferentially...in any organism. So what are the evolutionary constraints that lead to these preferences and what can we...therefore may need fewer resources for the entire translation process. For example, during high growth rate... tRNAs. For example Tuller et al. found that translation efficiency is well correlated with codon bias...tRNAs, different regions of the protein may be translated at different rates. The ribosome will move quickly...the ribosome stalls, this may give the swiftly translated regions a chance to fold properly. For example...
  15. Tips for a 1st time AAV user (by a Rookie AAV user)

    Type
    Blog Post
    Published
    Oct. 23, 2018, 11:49 a.m.
    ...sites). Another way is to transform AAV transfer plasmids into bacterial strains, like NEB Stable. NEB Stable...proteins to process a double-stranded intermediate into the single-stranded genome that's then packaged...viral replication; and 3) the transfer plasmid which encodes a transgene of interest that’s packaged into...particles for efficient gene transfer. I figure it’s better to have a bit extra AAV than to have to produce... iodixanol gradient ultrafugation Overview: Iodixanol gradient ultracentrifugation uses a gradient of ... share some AAV production, purification, and titration tips, while also summarizing the basic steps and...Overview: The first step in packaging AAV is transfecting HEK293 cells with AAV packaging plasmids. The...
  16. Better Dyeing Through Chemistry & Small Molecule Fluorophores

    Type
    Blog Post
    Published
    Sept. 8, 2016, 2:30 p.m.
    ...Figure 1f). Labeling strategy pros and cons All of these labeling strategies have trade-offs between the ...proteins. In-cell labeling strategies The majority of in-cell labeling strategies have two parts: (1) a genetically...(Figure 1c). Click chemistry (e.g., transcyclooctenetetrazine)– Nonnatural amino acids can be incorporated...labeling strategies and improved fluorophores are making chemical dyes increasingly attractive and accessible...once exclusive to small-molecules: red-shifted spectra, ion sensitivity, photoactivation, etc. These impressive...before bleaching. The amount of information one can extract from a biological sample is wholly dependent on...requires more photons. For example, moving from transient overexpression of protein fusions to gene-edited...
  17. Plasmids 101: The Promoter Region – Let's Go!

    Type
    Blog Post
    Published
    April 3, 2014, 8:05 p.m.
    ...General expression mRNA Tetracycline response element promoter Inducible with Tetracyline or its derivatives... low basal activity and several tetracycline operators. Transcription can be turned on or off depending...for in vitro transcription, the promoter drives either the sense OR antisense transcript depending on ...expression through varied inducer concentrations.  Sp6 in vitro transcription/ general expression Promoter...This element is responsible for initiating the transcription of your insert into RNA. In practice, the term...
  18. Quick Guide to Working with Drosophila Part 3: Genome Engineering in Flies

    Type
    Blog Post
    Published
    July 28, 2017, 1:30 p.m.
    ...have to make a transgenic fly in order to study it. The process is fairly straightforward. Basically, you...you need to combine multiple transgenes in one fly, having the transgenes in different loci allows for...brief introduction as to how you can engineer new transgenic flies to study your favorite gene (YFG).  Sometimes...plasmids at Addgene Choosing a vector to generate a transgenic fly There are a few important points to consider...that you can control exactly in which locus your transgene ends up (1): Random insertion has the advantage...you can get varying expression levels of your transgene in different fly lines. Also, if there is a chance...for genetic recombination so that the transgenes can be inherited on the same chromosome. Targeted Insertion...
  19. All in a Twist: dsRNA

    Type
    Blog Post
    Published
    Feb. 2, 2023, 2:15 p.m.
    ...Transcription, translation, and prone to degradation – those are the words that describe RNA! Double ...in our cells in the single strand form, but double stranded RNA and RNA:DNA hybrid molecules both exist...arise from a ssRNA engaging one strand of a dsDNA molecule; the 3-stranded structure produced is known as...intermediates in the process. These transcription-coupled R-loops are transient in nature and will dissociate...dissociate when gene transcription is complete. However, transcription of thousands of genes is constantly occurring...engages one strand of a dsDNA molecule, it does so at the expense of the unpaired DNA strand. A ssDNA molecule...Double stranded? Well, that’s just for DNA – right? RNA performs almost all of its biological functions in...
  20. Great Results Start with Great Standard Curves

    Type
    Blog Post
    Published
    Aug. 15, 2024, 1:15 p.m.
    ...sample of known concentration and measure a specific response as a function of the concentration. You then ...plot the concentration of the standards versus the response and use that information to extrapolate the concentration...spectrophotometer and concentration versus absorbance is plotted for the known concentrations (standard curve... a function of concentration on a scatter plot. For the BCA example, the concentration of each serial ...the trendline is calculated, you can extrapolate the concentration of the unknown sample based on its measured...calculated. The concentration of an unknown sample is determined by using the trendline to extrapolate its x value...standard curves with ELISAs to measure allergen concentrations in food; and your friend the grad student relies...
Showing: 101 - 120 of 862 results