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  1. Using AAV for Neuronal Tracing

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    ..., and enzymes for transmitter synthesis. Retrograde transport is used for transport of endocytosed material... facilitate transport: retrograde transport relies on dynein, while anterograde transport relies on kinesin...take advantage of existing transport pathways in neurons. Anterograde transport is typically used for the...mechanisms of trans-synaptic trafficking are not fully understood and may be a form of transcytosis where the...after intracellular transport without actually causing infection or leading to transgene expression within...endothelial transcytosis (Foust et al., 2009; Merkel et al., 2017), and these two modes of transport may share...optogenetically controlled transgenes, in combination with conditional transgenic mice, to reveal not only...
  2. Sleeping Beauty Awakens for Genome Engineering

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    ...contains the transposase gene (red) for expressing the transposase enzyme.2.) The transposase enzyme is ...which cuts the DNA.3.) The released transposon can now bind a strand of DNA with a TA dinucleotide (there...removal of the transposon; the plasmid is then degraded by the cell.4.) The transposase creates a double...double strand break in the DNA and allows the tranposon to integrate. Additionally, the TA sequence is duplicated....   The Sleeping Beauty transposon system The Sleeping Beauty (SB) transposon system is one such system...perform gene transfer in vertebrates. The system is comprised of 2 components: 1) an SB transposase, the enzyme...enzyme required for catalysis of transposition; and 2) a transposon containing the gene-expression cassette...
  3. Delivery Methods for Generating iPSCs

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    ...piggyBac (PB) transposon: The PB transposon is a mobile genetic element that transposes via a “cut and...Generates transgene-free and vector-free cells Limited genomic integration Multiple transfections required...Delivery DNA-Free High High Transgene-free and vector-free Multiple transfections required Protein Delivery...vector, but transient expression of Cre recombinase allows for deletion of the inserted transgenes that are.... This system is transfected into cells as a donor plasmid containing the transposon, along with a helper...sequences, which the PB transposase recognizes. Following reprogramming, transgenes can be removed by re-...also includes measles and mumps. Sendai transduces a wide range of cell types and replicates in the cytoplasm...
  4. Quick Guide to All Things Lentivirus

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    ...forming membrane pores) transfection. These techniques are still used and efficiently transfer plasmid...and stable expression of the transgene   Transfer plasmids The transfer plasmid is the vector you clone...comes to transferring DNA into primary cells or non-dividing cells. To target these un-transfectable cells...Dox), the Tet-controlled transactivator (tTA, also expressed by your transfer vector) binds to the TRE...production and transduction Once you have cloned your gene of interest into lentiviral transfer vector, the...will first need to transfect producing cells, usually 293T cells, with your transfer plasmid and your packaging...you don’t have any experience in transfection, CaCl2 transfection is a simple and cheap technique that...
  5. Technical Design of a Western Blot

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    ...covers a size range appropriate for the target(s) and transfer method. Membranes The two membrane options ...) steps to the transfer: you’ll need to pre-wet most PVDF membranes before the transfer and allow them...Types of transfers Your transfer options are wet, semi-dry, or dry/electroblot. A wet transfer is the most... while semi-dry transfers require a semi-dry transfer cell. Dry/electroblot transfers only work in the...low-background PVDF membrane, it also has higher background noise than nitrocellulose membranes. Pro tip! You...visualize proteins on a PVDF membrane without staining; simply wet your membrane with 20% methanol and place..., meaning that it will transfer the most protein from your gel to your membrane. It requires anywhere ...
  6. 28 Hot Plasmid Technologies from 2015

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    ...variant of PSmOrange, a photoswitchable fluorescent protein which transitions from emitting orange (λ= 565nm...enhancement of transcriptional activation via binding of multiple copies of a transcription factor to a ...the stop codon. Thus a non-translated mRNA will appear yellow, but a translated mRNA will be red. This system... were untranslated in the nucleus, confirming the hypothesis that most mRNAs are not translated until ...P-bodies are translationally repressed whereas the nonsequestered pool goes on to initiate translation. These...tool can also be used to visualize translocations, genome rearrangements and cancer-associated chromosome... been used to study transport characteristics of various Golgi and plasma membrane reporters as well as...
  7. Antibodies 101: The Basics of Western Blotting

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    ...systems efficiently transfer a range of protein sizes in minutes without any transfer buffer. These systems...proteins are: (1) separated by size, (2) transferred to a membrane, and  (3) detected using antibodies. ...mixture of protein is separated in a gel, transferred to a membrane, stained with antibodies, and finally ...a broad size range to be separated on a single gel.  Immobilizing proteins on a membrane Once separated...migrate out of the gel and attach to the membrane.  In a wet transfer system the sandwich is completely submerged...filled with a transfer buffer formulated to conduct the electric current. The wet transfer process is very... very effective in transferring a broad range of protein sizes but takes hours to overnight.  In contrast...
  8. Plasmids 101: Terminators and PolyA signals

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    ...initiation step of gene transcription; today we'll provide an overview on how transcription stops, or termination...from the transcription machinery. Terminators are found downstream of the gene to be transcribed, and typically...generally serves to promote transcript longevity in eukaryotes and promote transcript degradation in prokaryotes...thought to destabilize the transcription complex, initiating cleavage of the transcript.   Figure 1: ...Hepatitis Virus Posttranscriptional Regulatory Element Enhances Expression of Transgenes  Delivered by ...terminators in the context of AAV transgene expression levels. Transcription Termination Rho-dependent termination...both prokaryotic and eukaryotic systems must be transcribed into RNA, which occurs in three phases: initiation...
  9. Minigenomes - a Safe Way to Study Dangerous Viruses Like the Ebola Virus

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    ...gene transcription (6). The EBOV genome contains seven viral genes, each flanked by a transcription start...replicated and transcribed in the cell when the appropriate viral proteins are provided in trans (see Other...genes and the minigenome are transcribed (and the viral mRNAs are translated) by cellular machinery. NP ...altering the amount transfected (see Technical Tips). Minigenome replication and transcription In order to replicate...it will terminate transcription and polyadenylate the mRNA. These mRNAs are translated by cellular host... lines that are highly transfectable.  The amounts of each plasmid transfected into cells are also extremely...interested in genome replication and transcription of negative strand RNA viruses.   References 1. Buchholz...
  10. Technique: Probe Phage Genomes for Host Binding Proteins

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    ...plates. Step 2: Express random phage DNA fragments in E. coli Now that random DNA fragments have been ...nitrocellulose membranes and exposed to IPTG in order to induce protein expression. Cells on the membranes will ...orientation of each membrane on its plate before moving on. Then peel each membrane off the plate (saving...high salt.  To probe membranes with target bacterial cells, wash your membranes with PBST to remove salt... on the membrane to bind their target cells, pulling them out of solution. Wash your membranes well with...searches return no candidates. Our strategy: Express random fragments of the phage genome and probe with live...identified using this method. Step 1: Prepare a random fragment library of phage DNA This first step involves...
  11. Prime Editing: Adding Precision and Flexibility to CRISPR Editing

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    ... non-edited strand, they can cause the cell to remake that strand using the edited strand as the template...the nicked target strand. The initial result is a heteroduplex, with overlapping strands of edited and unedited...Improving reverse transcriptase efficiency Building upon prior reverse transcriptase research, the Liu...the edit into one strand, there’s a mismatch between the original sequence on one strand and the edited ... the unedited strand away from the initial nick site (to avoid creating a double strand break), increasing...binds the edited strand, as in the PE3b system, guides nicking of the unedited strand only after editing...process and promote copying of the edited strand to the unedited strand (Chen et al., 2021). The team applied...
  12. Plasmids 101: Mammalian Vectors

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    ... does not guarantee 100% transfection efficiency. Stable transfection A stable transfection is used to...process called transfection. Transfection is somewhat comparable to bacterial transformation (the introduction...the transfected plasmid to be expressed transiently. Since the DNA introduced in the transfection process...the genome to form a stable transfection. Unlike bacterial transformation, scientsts do not "select" for...fluorophore in a later post, so stay tuned! Transient transfection and the elusive "mammalian ORI" For many...plasmid depleted, but still want to use transient transfection methods. Since there are no "natural" mammalian...must be compatible with the cell type they are tranfected into – a bacterial origin of replication (ORI...
  13. Your Lentiviral Plasmid FAQs Answered

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    ...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...
  14. Antibodies 101: Stripping and Reprobing Western Blots

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    ... 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...you need to start a whole new blot? Never fear: membrane stripping is here! Rather than start over, you...
  15. Viral Vectors 101: Gamma-Retroviral Packaging Systems

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    ...γ-Retroviral transfer plasmid encoding a transgene, sgRNA, or shRNA of interest: The transgene sequence is...packaging and transduction are not encoded by the transfer plasmid, but instead are provided in trans by other...integrated into the host genome upon viral transduction. Most transfer plasmids available from Addgene were ...packaging, and transfer) are supplied by three types of plasmids, which are cotransfected into the 293T...cell line. γ-Retroviruses can transduce target cells, but the transduced target cell does not produce ...protein containing Reverse Transcriptase and Integrase components. Transfer cPPT Central polypurine...proviral DNA synthesis. Increases transduction efficiency and transgene expression. Psi (Ψ) RNA target...
  16. Important Considerations When Using AAVs

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    ...their efficiency at transducing different brain regions. Although AAV2 can transduce many tissue types,...Axonal Transport It has been demonstrated that certain serotypes can undergo axoplasmic transport. These...of neurons (retrograde transport) or towards the synapse (anterograde transport), which is a possible ...retrograde and anterograde transport, but they also have similar transport characteristics (velocities...strong CNS tropism (4). If axonal transport is not desirable, transport can be reduced by injecting a smaller...scAAV) (7). As single stranded DNA viruses, AAVs normally require second strand synthesis before gene ...Simon Rumpel. "Analysis of transduction efficiency, tropism and axonal transport of AAV serotypes 1, 2, 5...
  17. Deep Mutational Scanning with One Pot Saturation Mutagenesis

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    ... by the bottom strand versus nicking the bottom strand first followed by the top strand. Both produced...complementary mutant strand (step 2 and 3). Then the uracil-labeled template strand is degraded by uracil...present on both strands of the plasmid. The ssDNA template is generated by transforming a backbone phagemid...ExoI then fully degrades the nicked strand. Synthesize mutant strand: A mix of degenerate primers and the...synthesized DNA strand. Each degenerate primer set contains three consecutive randomized bases (NNN) at...Degrade wild-type template strand: Next, the opposite wild-type DNA strand is nicked by the BbvCI variant...step 1. Then this strand is degraded with ExoIII and ExoI. Synthesize 2nd mutant strand: The second mutant...
  18. Plasmids 101: Repressible Promoters

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    ... polymerase and transcription factors. Since the promoter region drives transcription of a target gene...repressor then prevents transcription from occurring, which means that transcription is now OFF.   We’ll...tetracycline-controlled transactivator (tTA). They fused TetR with the transcriptional activation domain VP16...other. For example, the GAL4 transcription factor cannot drive transcription from the QUAS promoter, and...and the QF transcription factor cannot drive transcription from the UAS promoter. This is important because...Repressible: An activator protein is bound, turning transcription ON. When a repressor binds the activator protein...cannot bind the promoter sequence anymore and transcription is turned OFF. Negative Repressible: A repressor...
  19. Multiplex Genome Editing with CRISPR-Cpf1

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    ...the usual transfection drawbacks: transient expression and needing to work with a transfectable cell line...Cassettes transfection gRNAs expressed from a polycistronic transcript  Requires co-transfection of Cas9...Cassettes transfection gRNAs expressed from a polycistronic transcript Requires co-transfection of Cas9  ...expression platforms: transfection, lentiviral transduction, and AAV transduction.  In most of Zetsche ... rely on transfection of more than one vector to express the gRNAs and Cas9. Co-transfections can lead... GFP tag were transfected on a single plasmid. This is versus 2.4% of cells transfected with a pool of...multiple applications (in vitro, in vivo, transfection, viral transduction) for simultaneous multi-gene editing...
  20. All in a Twist: dsRNA

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    ...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...
Showing: 221 - 240 of 986 results