We narrowed to 847 results for: ple
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TypeBlog PostPublishedFeb. 22, 2022, 2:15 p.m.... amino acids, HA is nine), multiple repeats of the tag can recruit multiple frankenbodies to amplify the...ever like to write about a recent plasmid deposit please sign up here. Here's what you'll find in this...genetic screening technique using Cas12a for multiplexed gene perturbation The Penn State Protein Ladder...Anti-FLAG frankenbody (FB) construction from the complementarity determining region of an anti-FLAG scFv and...genetic screening technique using Cas12a for multiplexed gene perturbation by: Gabrielle Clouse While ...method for screens. Cas12a’s ability to perform multiplex editing within a single expression cassette is...vs. Cas 12a expression cassettes when encoding multiple guides. While two guides require two arrays for...
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Evolution of Lab Techniques
TypeBlog PostPublishedJune 21, 2016, 2:30 p.m....fluorescently labeled probe. If the DNA is complementary to the probe (for example, has the sequence of the mutated...searching for), then the probe will bind to the sample thereby labeling it. The label can then be visualized...strength of the signal in comparison to a control sample. Southern blotting applications range from confirming...experiments to forensics and clinical diagnostics. One example of southern blotting being used to identify a gene... MstII and southern blotting are conducted on a sample from an individual without sickle cell anemia, ...DNA sequences to see which is more abundant in a sample. Whereas Southern blotting is labor intensive and...different restriction enzyme digests. Incubating a DNA sample of unknown sequence with restriction enzymes and... -
Targeting HIV-1 with CRISPR: Shock and Kill or Cut it Out?
TypeBlog PostPublishedMay 10, 2016, 2:30 p.m....mutations. Multiple gRNAs could be used to combat this problem, just as ART includes multiple drugs to ...Over 25 million people worldwide are currently infected with the lentivirus HIV-1. Today, HIV-1 can be...undetectable in the blood. But the virus doesn’t completely disappear; it just hides in latently infected...accomplish this tough job! Kamel Khalili’s lab at Temple University has demonstrated two potential strategies...the immune response. The second strategy is the simple removal of the HIV-1 genome from infected cells...transcriptional activation. Zhang et al. designed multiple gRNAs to target the 5’ long terminal repeat (LTR...activation of HIV promoter-luciferase constructs. In multiple HIV-1 latent T cell lines, as well as a latent... -
Antibodies 101: Fab Fragments
TypeBlog PostPublishedSept. 5, 2024, 1:15 p.m.... antibody complexes before applying them to samples, such as when performing IHC in a sample where your...gives you a better chance of getting the complex into the sample. Alternatively, Fab fragments can be used...proteolytic approaches. This comes in handy when, for example, you want to swap out one isotype for another. ...antibody in isolation from another portion. For example, Fab fragments are molecules composed of just the...antibodies. Their smaller size allows them to get into samples more efficiently and can also improve localization...antibodies bound together may be too large. Using a complex that is one full antibody bound to a Fab fragment...same species as your secondary antibody to your sample prior to adding your primary and secondary antibodies... -
Antibodies 101: Selecting the Right Antibody
TypeBlog PostPublishedMarch 15, 2022, 1:15 p.m.... as these immune complexes are smaller than a primary:secondaries:conjugates complex. If you are trying...Antibody-based assays are complex and antibodies may perform differently in different samples and experimental ...primary (linear) structure using heat or acid, for example in a Western blot. If you were to try and use such...all IHC experiments are the same. Differences in sample processing, fixation, antigen-retrieval, and permeabilization...chance that the antibody could meet your needs. Multiplex experiments Finally, consider whether you will... in the experiment. If you are planning to use multiple antibodies in a single experiment then you will...antibodies are sold under different names through multiple vendors, so look at epitope target, source, and... -
Tagging Optogenetics and Chemogenetics Receptors: Fluorescent Proteins and Other Options
TypeBlog PostPublishedMay 11, 2021, 1:15 p.m....reveal the hM4Di coupled to mCherry (top) or HA tag (bottom). The images show examples of dendrites (blue...interest. Furthermore, fluorophore variants (for example green and red fluorescent proteins) allow simultaneous...properties or trafficking of the fusion protein (Kimple et al., 2013). We found that the fluorescent proteins...The hM4Di receptor is an engineered Gi protein-coupled receptor, one of the Designer Receptor Exclusively...antibodies against mCherry, and secondary antibodies coupled to nanogold particles, that allow a high-spatial...needed, the use of HA and other short epitope tags (Kimple et al., 2013) could help improve the transport ... not generalizable to all fusion proteins. For example, we saw that another type of DREADD, hM3Dq, is ... -
Selecting Your Plasmid Purification Kit
TypeBlog PostPublishedMay 27, 2025, 1:15 p.m.... is completely degraded. Cloning Grade DNA (high quality/low quantity) – You can usually complete a cloning...transfection-grade While we’ve included a sample of some commonly used kits, please note that Table 3 is certainly...plasmid DNA itself, which can happen if you leave the sample in a lysis buffer for too long or if you get a ...easier than others to prevent quality issues. For example, some kits reduce the risk of ethanol carry-over...you mix specially coated magnetic beads into your sample and use magnets to isolate the beads for the wash...Take your average column-based miniprep kit for example. These kits are designed to handle ~1–5 mL of liquid...can affect the lysis buffer ratio and result in incomplete lysis. You may be able to scale the amount of... -
Antibodies 101: Stripping and Reprobing Western Blots
TypeBlog PostPublishedAug. 1, 2024, 1:15 p.m....membrane will remove some of your sample —and harsher stripping means more sample loss. If you are still optimizing...you want to detect more than one protein in your sample? Or what if something weird happened during your..., almost like new. This approach preserves your sample and saves you from having to run a whole new gel... of time that you want to probe your blot with multiple antibodies. You’ll want to set up your blot with...stripping solution (see below) to minimize loss of your sample from the membrane. Next, plan out the order of ...stripping methods. If you are planning to detect multiple proteins through several rounds of stripping and... the weaker binding ones first to preserve your sample. Pro tip! Because some protein is lost each time... -
Overcoming the Challenges of Lentiviral Production
TypeBlog PostPublishedAug. 7, 2018, 12:31 p.m....dish can be easily applied to multiple dishes, remember that handling multiple dishes will take longer and...packaging systems divide the viral elements among multiple plasmids. Second generation packaging systems ...transfer gene. By dividing the viral elements across multiple plasmids, the risk of recombination and consequently...different generations of lentiviral packaging systems please see Addgene’s Lentiviral Guide. While the third...plasmid are not always the best for others. For example, in our hands we find that a double harvest approach...larger genes such as Cas9. See figure 1 for an example of how changing transfection ratios can affect ... volume than with the unconcentrated prep. For example, at Addgene we typically concentrate 100-fold meaning... -
Split-BioID: An Improved Method for Studying Protein-Protein Interactions
TypeBlog PostPublishedMay 1, 2018, 1:57 p.m....biomolecules. They can be part of multiple dynamic and overlapping complexes that have distinct functions....biotin-containing media. FRET is another example of a protein fragmentation complementation assay that can be used to...proteins that interact with a particular protein complex as opposed to an individual protein. The Bethune... when the bait is part of a particular protein complex. Not performed in a native cell context. For AP-MS...experiment is called a protein fragmentation complementation assay (PCA). In the Split-BioID method, each...Protein Interactions. Split-BioID is a protein complementation assay where BirA*, an E. coli biotin ligase...proteins Y and Z interact, the two BirA* fragments complement each other to form a functional BirA* enzyme.... -
Quickest Way to Deposit Plasmids: The Deposit Spreadsheet
TypeBlog PostPublishedMarch 8, 2017, 3:15 p.m....plasmid deposit process can be broken down into four simple steps: Send plasmid information to Addgene Material... explain how to use our deposit spreadsheet to complete Step 1. Steps 2 and 3 are usually very easy — ... “Download Deposit Spreadsheet” (see Figure 1). Please read our “How to Deposit Your Plasmids with Addgene... a collection that is greater than 75 plasmids, please contact us at [email protected]. These deposits...any functional consequences of that change. For example, “Mutated aspartate 123 to Lysine (D123K), lowers...indicate type in “Vector Type Other” column. For example, you may enter “donor template vector”. Cloning...37 °C, or room temperature. Growth Strain Please indicate which growth strain Addgene should propagate... -
Golden Gate Assembly Upgrades: More Fragments, Faster Assembly, and Higher Fidelity
TypeBlog PostPublishedOct. 11, 2018, 12:30 p.m....with increasingly complex experimental conditions. The ability to construct more complex, multi-fragment...fragments in a single “one-pot” reaction to form complex, multi-insert modular assemblies that enable biosynthetic...enzyme cutting results in 5’ four base overhangs complementary to the overhangs of the assembled inserts. After..., the BsaI site is no longer present, allowing multiple fragments to be assembled in an ordered, pre-determined...assembly Intermediate 5- or 12-fragment assembly More complex 24-fragment assembly Single insert cloning efficiencies...Sequencing of blue colonies showed the expected complete sequence for the lacI/lacZ genes (1), while sequencing...single omission should block the formation of a complete assembly that would result in a blue phenotype... -
AAV Vector Quality Control: Going the Extra Mile with NGS
TypeBlog PostPublishedSept. 12, 2017, 1:44 p.m.... DNA and processed the mixed sample in our pipeline (see Figure 2, sample 2). When we blindly analyzed...questions are especially important when producing multiple vectors in parallel because the risk of accidental...in-house sequencing capabilities and Seqwell’s plexWell technology, we can now perform NGS at Addgene ...these known impurities, as was the case for clean sample AAV-44362. In addition to these expected hits, ...to “random” genes. Do these hits always mean the sample is contaminated? No - what really matters is the...of hits to the same sequence (gene). In a clean sample, there are typically fewer than 10 hits to a given...>100 hits - immediately raises a red flag. For example, AAV-68544 contained 220 hits to the CHRM4 gene... -
Experimenting with New Careers while in Grad School
TypeBlog PostPublishedFeb. 25, 2016, 3:30 p.m....academia One recent example: Don't call me a dropout: Why science needs more people to quit the lab. ...re provided throughout your PhD program. Find people who will support your professional development ...are not as supportive of your career goals, find people who are. I wanted to do fun science activities ...activities with the public, so I reached out to people who were educating the public and organizing events. I contacted...attention on social media. I gained a concrete example to use to promote future attempts and learned a...try new things, develop new skills, and meet new people. There were visiting seminar speakers each week...meet with various professionals, and there were multiple avenues for professional development including... -
Drew Endy Introduces the Biobrick Public Agreement Plasmid Collection
TypeBlog PostPublishedDec. 12, 2013, 3:35 p.m.... useful they are implemented in most materials that have been engineered. For example, Boole’s logic shows...biological engineering openly so as to benefit all people and the planet. For his many efforts in open science...BioBricks Foundation to distribute the physical DNA samples, for when that's the preferred mode of receiving...phrase we like to use is 'the parts must flow.' People must be able to use genetically encoded functions... for engineering an entire cell. Typically when people use plasmids, they are trying to do one thing at...Integrase Logic (BIL) gates collection of parts implements the basic logical functions, which we know and..., computers, and now through BIL gates we've implemented them in DNA. We thought these were so much fun... -
Cre-ating New Methods for Site-specific Recombination in Drosophila
TypeBlog PostPublishedMay 12, 2015, 1:32 p.m....to make complex genome modifications in Drosophila using multiple recombinases. To make multiple, precise...recombination by KD, B2 and B3 resulted in complete or near-complete excision of the stop sequence. In contrast...to DNA damage and developmental aberrations. In multiple systems, Cre itself, without the presence of a...toxicity, but with the caveat of partial rather than complete recombination. If you’re looking to use site-specific... high recombinase levels. These data show that multiple recombinases can be used together to designate...for specific recombination patterns that require multiple recombinases. These tools should further enhance...editing capabilities in Drosophila. References: Multiple new site-specific recombinases for use in manipulating... -
When Fidelity Matters: A frank discussion about ligase fidelity
TypeBlog PostPublishedMarch 6, 2018, 1:49 p.m.... (5,12,13). For example, in the Ligase Detection Reaction (LDR), probes complementary to the sequence ... extended to multiplexed probe sets that allow the simultaneous interrogation of multiple potential SNP...ligation of fully base-paired nicks with no gaps. For example, DNA assembly methods, such as Gibson Assembly®...without the exo/polymerase generation of annealed complementary regions. Why use a high fidelity ligase? Numerous...extends earlier studies through a high-sensitivity multiplexed format (21, 27). This methodology has been used...separate pools were prepared, each with a different complement strand covering all 16 possible NN pairs in the...Stefan V., and Göran Magnusson. "Sealing of gaps in duplex DNA by T4 DNA ligase." Nucleic acids research 10.5... -
Plasmids 101: Codon usage bias
TypeBlog PostPublishedSept. 27, 2018, 1:09 p.m.... encode which amino acids (see example to the right). With such simple rules, you might think it’s easy...codons unaccounted for. The result is redundancy; multiple codons encode single amino acids. Evolutionary...varied codon preferences among organisms aren’t completely understood, but some possible reasons include...resources for the entire translation process. For example, during high growth rate conditions, E. coli preferentially...encoded by highly abundant, charged tRNAs. For example Tuller et al. found that translation efficiency...translated regions a chance to fold properly. For example Pechmann and Frydman found that tracts of non-optimal...producing and charging specific tRNA pools. For example, tRNAs used in genes encoding amino acid biosynthetic... -
Important Considerations in Optogenetics Behavioral Experiments
TypeBlog PostPublishedOct. 1, 2015, 2:30 p.m....fully summarized in a short blog post, but some examples I’m personally interested in include: intracranial... is an approximation of reward or the sense of pleasure that the animal perceives through taking a drug... also models reinforcement but is considerably simpler than ICSS. The test chamber is divided into two...expression of the early response gene c-fos. For example, using Chr2 stimulation should result in robust...c-fos expression to get the evidence you need. For example, as shown in this study [3], hippocampal neurons...mouse is placed in a novel context. As a proof-of-principle test, the authors were able to show that HR blocked...involved in regulating the behavioral output. For example, if you are interested in studying a brain region... -
Antibodies 101: Chimeric Antibodies
TypeBlog PostPublishedApril 25, 2023, 1:15 p.m....will not affect single-plexed experiments, it needs to be addressed when multiplexing. It is imperative that...cannot be indirectly probed simultaneously on the sample. What to do? If you’ve ever found yourself facing...the constant regions from an alternative isotype (purple, mouse). Depending on the cloning process, all ...conversion, gives users the flexibility needed for multiplexing. In the case above, you can’t costain with your...visualize both targets in parallel (Fig. 2). For example, if both of your antibodies are rat IgG1, then ...antibodies with the same isotype can not be used for multiplexed indirect staining methods since the secondary...the new Fc region. In addition to increasing multiplexing capabilities this process is frequently used...