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  1. Polymerase Chain Reaction Overview and Applications

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    Blog Post
    ...separation of the two DNA strands.  Annealing- The temperature is then dropped to a range in which the forward...the primers can anneal to the single stranded DNA template strands. DNA polymerase is also stable at this...template DNA to amplify from and unique single stranded DNA primers that bind upstream (5’) and downstream... process as DNA polymerases require an existing strand of DNA to add nucleotides to.  Using these reagents...reaction:  Denaturation- To amplify DNA, the two strands of the template DNA first have to be separated....used to quantitate RNA levels using reverse transcription-qPCR (RT-qPCR). The first step of this process...requires RNA to be converted to cDNA using reverse transcription and the cDNA is subsequently quantified by qPCR...
  2. Which Fluorescent Protein Should I Use?

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    Blog Post
    ...or Förster] resonance energy transfer). FRET occurs when energy transfer from one FP (e.g. CFP) excites...classified by the emission color (emission wavelength range) FPs are usually classified by emission color as...as outlined below (or emission wavelenght range).  By mutating GFP, the variants blue FP (BFP), cyan FP...nm Green 499 - 519 nm Yellow 524 - 538 nm Orange 559 - 572 nm Red 574 - 610 nm Far-Red 625 -... ≥ 670 nm In addition to emission wavelength range, there are other traits that need to be considered... green or red light. For example, T-Sapphire, LSSmOrange, and LSSmKate. Fluorescent Sensors: These FPs...related colors. Furthermore, most FPs  have a broad range of emission which will be detected by longer-wavelength...
  3. Why Do I Need an MTA Anyway?

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    Blog Post
    ...Uniform Biological Material Transfer Agreement (UBMTA) for its material transfers. The UBMTA was drafted by...organizations Assurance that recipient may not use the material for a commercial purpose Assurance that recipient... has time for paperwork? Here’s why a Material Transfer Agreement (MTA) matters: Science thrives on collaboration...universities and institutions require them for material transfers. When Addgene entered the plasmid sharing space...receiving institution. Therefore, many technology transfer officers are familiar with the UBMTA and are happy...  material transfer agreement...
  4. Simplify Cloning with in vivo Assembly

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    Blog Post
    ...false positive colonies. Transformation - the linear fragments are transformed into E. coli and plasmid...assembly of a circular plasmid in vitro, before transforming it into E. coli for propagation. However, while...using a simple two-step, 2 hr protocol prior to transformation (Figure 1). As this approach requires no special... encode homology arms to allow immediate co-transformation with linearized vector backbone. DpnI digestion...failed so far. What is most important is the transformation efficiency of the strain: when asking the cell...high fidelity DNA polymerase This will minimize random errors during PCR: we recommend Phusion or Q5. ...investigating the molecular biology of synaptic transmission and plasticity.     Javier García-Nafría is ...
  5. Droplet Digital PCR for AAV Quantitation

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    Blog Post
    ... dilution should fall within the range of the assay for a wide range of titers. We usually dilute our ...determine if your titers are within the expected range. We have also found that generating the standard...For these reasons, we are in the process of transitioning our titering method from qPCR to ddPCR. Droplet...virus. It is important to note that the dynamic range of the ddPCR is between 1 and 100,000 genome copies...per reaction. Since AAV titers tend to be in the range of 1012 to 1013 GC/mL, you must serially dilute ...million.  After making the dilutions, they are transferred to a new plate containing the mastermix which...generator, you will have to be careful about transferring your droplets from the droplet generator to ...
  6. Isolating Genomic Regions of Interest with the CRISPR System

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    Blog Post
    ...dCas9 has focused on transcriptional activation using a fusion to a transcriptional activator such as VP64...repression of transcription through binding a promoter region to inhibit association of transcriptional activators...locus of interest, the promoter region of the transcription factor IRF-1. Immunoprecipitation, using an ...2018). Furthermore, the Fujii Lab generated a transgenic mouse line and retroviral expression system for...Tapscott Lab identified regulators of DUX4, a transcriptional regulator that when inappropriately expressed...PMCID: PMC6001023. Fujita, Toshitsugu, et al. "Transgenic mouse lines expressing the 3x FLAG‐dC as9 protein...CRISPR-mediated modular RNA-guided regulation of transcription in eukaryotes." Cell 154.2 (2013): 442-451. ...
  7. Interview: Hodaka Fujii on enChIP, New CRISPR Tools, and More

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    Blog Post
    ... inducible translocation trap (ITT) system to analyze signal-induced nuclear translocation of proteins...functions such as epigenetic regulation and transcription by using locus-specific chromatin immunoprecipitation...biochemical analysis of genome functions such as transcription and epigenetic regulation. To elucidate molecular...Addgene realizes the One-Stop shopping for a wide range of plasmids. The merit of depositing plasmids to...considering the peer-review system of journals and grant applications, for example. However, at the same ...living for Japanese, which is not trivial, and the grant situation is currently much better than that in ...tough competition for academic positions and poor grant situation. So, young researchers need to publish...
  8. Illuminating Choices: A Guide to Selecting Fluorescent Dyes and Ligands

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    Blog Post
    ... of fluorescence: For applications that involve ranges of pH, and significant lengths of time, the stability...receptor conformation and signaling activity​​ (Sridharan et al., 2014). It's also crucial to evaluate how...the background. Dyes that can pass through cell membranes can prove useful for live-cell imaging. Experimental...considerations regarding the choice of fluorescent dyes (Sridharan et al., 2014). Manufacturers will typically recommend...accurate tagging. In Fluorescence Resonance Energy Transfer (FRET) applications, the dyes need to have compatible...and emission profiles to enable effective energy transfer, which is key to observing interactions and conformational... specifically to the AT-rich regions of double-stranded DNA and exhibits a blue-fluorescent light when...
  9. A Primer on Optogenetics: Introduction and Opsin Delivery

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    Blog Post
    ...injections can be found here [5, 6]. Opsin transgenic mice Transgenic mouse lines have also been engineered...specific brain region can result in a particular neurotransmitter release or post-synaptic current. Fortunately...available, instructions for obtaining a material transfer agreement, and list of vendors (such as the vector...at a similar spectrum as HR and also results in membrane hyperpolarization but unlike HR, this is achieved...[10]. Unfortunately, opsins are not actively transported and must passively diffuse so, depending on the...axonal tracing with fluorescent proteins in nontransgenic and cre driver mice. Current protocols in neuroscience...et al. A toolbox of Cre-dependent optogenetic transgenic mice for light-induced activation and silencing...
  10. Hot Plasmids - August 2020

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    Blog Post
    ...protease allows a transcription factor to enter the nucleus and modulate transcription of the mCitrine ...HeLa cells were transfected with plasmids encoding FPs tagged with the plasma membrane targetin sequence...non-specific labeling. For labeling the plasma membrane, they tested different target sequences for improved...expression can vary significantly depending on transgene design and delivery. To overcome these variations...into genomic DNA with the help of the piggyBa transposase. Image from Hazelbaker et al., 2020. The lab...activating expression of TCF4 while monitoring transcript and protein levels. Plasmids for multiplexed ... new serotype PHP.V1 that exhibits efficient transduction of vesicular brain cells. Find this AAV at ...
  11. Finding nucleic acids with SHERLOCK and DETECTR

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    Blog Post
    ...amplification) or reverse transcriptase (RT)-RPA, respectively. RPA is coupled with T7 transcription to convert amplified... method termed DNA Endonuclease Targeted CRISPR Trans Reporter (DETECTR) (Chen et al., 2018). Both SHERLOCK...almost anywhere as lateral flow strips are easy to transport and work rapidly, providing reliable results in...    DETECTR- DNA Endonuclease Targeted CRISPR Trans Reporter Cas12a (Cpf1) is a CRISPR Cas variant that...discovered Cas12a’s ability to cleave non-specific (trans) ssDNA and harnessed this ability to create a DNA...DNase activity of Cas12a is initiated. Surrounding trans-ssDNA, including the ssDNA-FQ reporter are subsequently...Servellita V, Singh J, Miao X, Streithorst JA, Granados A, Sotomayor-Gonzalez A, Zorn K, Gopez A, Hsu ...
  12. CRISPR Activation: A Practical Guide

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    Blog Post
    ...promoter of another gene, thereby driving aberrant transcription. That being said, we generally pick guides...been significant work on constructing Cas9 transcriptional activators. These constructs allow for the ...Cas9 deficient in DNA cutting activity to a transcriptional activation domain (Fig 1). Two ways to use...picking whichever guides are closest to the transcription start site (TSS). We recommend targeting the...Latency Reversal Using CRISPR/Cas9-Derived Transcriptional Activator Systems. PLoS ONE 11:e0158294 . https...Church GM (2015) Highly efficient Cas9-mediated transcriptional programming. Nat Methods 12:326–328 . https...Nishimasu H, Nureki O, Zhang F (2014) Genome-scale transcriptional activation by an engineered CRISPR-Cas9 complex...
  13. Three Key Considerations for Precise Neuronal Targeting Using AAV Technologies

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    Blog Post
    ... cell types. Specific transgene expression can be also achieved in nontransgenic animals by using cis ...delivery by increasing transgene cargo capacity, enhancing anterograde transport efficiency, and engineering...proteins that determine the AAV serotype. During transduction, the viral capsid proteins bind to the target...serotype used for a specific cell type. Find some transduction characteristics of select AAV serotypes in Table... AAV vectors are common approaches to control transgene expression by restricting expression to genetically...enhancers, multicistronic vectors, and post-translational regulatory elements. Examples of these approaches...
  14. Fluorescent Proteins 101: Fluorescent Biosensors

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    Blog Post
    ...enzyme or transcriptional activation, conformational changes, translation, and protein translocation. Targeting...triggers CaM/M13 interaction that increases FRET transfer between the fluorescent proteins. FRET is highly...characteristics like pH, redox state, and voltage across membranes. These sensors generally follow the same pattern...an organelle-specific targeting signal or a transmembrane domain, biosensors can be targeted to a particular...endoplasmic reticulum (ER), vacuole or cellular membranes. Examples include blue flame mitochondria-targeted...
  15. Antibodies 101: Single Chain Fragment Variables (scFvs)

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    Blog Post
    ... the CAR facilitates signal transduction and release of cytotoxic granules from the T cell. When a CAR...., 2012, Bates and Power., 2019): rapid blood clearance, which is useful for imaging applications; better...small size (Bates and Power., 2019). Their rapid clearance from blood can be a drawback for therapeutic applications... has led to their application for basic and translational research.  Basic research applications of scFvs...single molecule tracking in living cells. The HA frankenbody is an HA tag detection probe. It contains an ...to a fluorescent protein such as GFP. The HA frankenbody works just like an antibody-based probe, but ...generate since it’s genetically encoded.   Translational applications of scFvs: Just like antibodies...
  16. Tetbow: Bright Multicolor Labeling for Neuronal Tracing

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    Blog Post
    ...fluorescent protein (XFP) genes in a transgene. When multiple copies of the transgene cassette are introduced, stochasticity...fluorescent proteins is only possible at low copy number ranges, resulting in low fluorescent protein level. The...gene delivery is more common than conventional transgenic strategies. In such vector-based gene delivery...in the original method, we used the Tetracycline trans-activator system to boost the expression levels,...levels, and we named the system Tetbow (Tetracycline trans-activator Brainbow) (Sakaguchi et al., 2018) (Figure...expression level of XFPs, most likely by suppressing transcription. It is critical to express a minimal amount ...Bio-Protocol 8 (2018): e3046. Livet, Jean, et al. "Transgenic strategies for combinatorial expression of fluorescent...
  17. 5 Uncommon Ways to Gain Career Skills During an Uncommon Time

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    Blog Post
    ... and not in academia is run by grant funding. Learning to write grants quickly, efficiently and effectively...apply to or offer to help with lab grant writing. You may not get the grant or your PI may edit everything...thinking about future career options. 5. Write a grant - even if you don’t need one A lot of science in...valuable skill. There are many different kinds of grants that you can apply for. If you are in a lab, your...Here are some sites that have compiled lists of grants: Science: Where to Search for Funding The Ohio...For Your Research University of Florida: Training Grants and Other Funding Opportunities L’oreal USA For...
  18. Safe Port in a Storm...How Addgene is Weathering the Pandemic

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    Blog Post
    ...grateful to the grant officers at Fast Grants. We received a miraculous grant from Fast Grants, which was ...studying the coronavirus. Addgene’s Technology Transfer Team also moved fast to ensure that the majority...collaborations as well as provides visibility for grant-driven research being done in all labs sharing materials...materials via Addgene. Perhaps if each of many grantors supporting research could provide Addgene with... for supporting Addgene by providing a generous grant. This support will enable us to continue all operations...
  19. Hot Plasmids and Viral Preps - September 2021

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    Blog Post
    ...ready-to-use viral preps   Improved cell-free transcription/translation system to examine biosynthetic pathways... Gabrielle Clouse Recently, cell-free transcription/translation systems (also referred to as TX-TL systems...modifications to edit DNA without requiring a double-stranded break. The Xiao Wang Lab has recently deposited.... These plasmids use “Cas9-mediated adenosine transient reporter for editing enrichment”, or XMAS-TREE...and enrichment use of XMAS-TREE. a) Cells are transfected with three different vectors and flow cytometry...identification of essential MYC binding sites in a wide range of human cells.  A new pooled library from Junjie...
  20. Antibody Validation for Flow Cytometry

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    Blog Post
    ...method is transfection of short interfering RNA (siRNA). Knockdown caused by siRNA is also transient, and ...interest. This approach often involves the transient transfection of expression plasmids in a given cell ...commercially available. Various proteomic and transcriptomic datasets can be used to select a candidate ...antibody should be able to detect even in cells transfected with low efficacy. But since there can be large...differences between endogenous expression and transfected overexpression, this approach cannot confirm ...workshops. Let’s use TIM-1 (Single pass type-1 membrane protein), which has been designated CD365 in the...the antibodies both recognized the target when transiently overexpressed in CHO cells and displayed similar...
Showing: 421 - 440 of 986 results