We narrowed to 1,025 results for: URE
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TypeBlog Post...here and no viral progeny are produced (Figure 1). Figure 1: Comparison of the life cycle of a lentiviral...recombination or non-homologous end joining (see Figure 2). Figure 2: Schematic representation of integration...cell but cannot integrate it into the host genome (Figure 1). IDLVs were first discovered by researchers ...continuously expressed (Fu et al., 2013). Using IDLVs ensures transient expression without the risks associated...titering IDLVs, there is no integrated piece to measure! Instead, two commonly employed methods for titering...induced by CRISPR-Cas nucleases in human cells. Nature Biotechnology, 31(9), 822–826. https://doi.org/...
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Plasmids 101: Gibson Assembly and Other Long-Homology Based Cloning Methods
TypeBlog Post...insert into your vector of choice as shown in the figure below. To start, you need to have DNA fragments...enzymes is that they can all work at the same temperature, so the entire reaction takes an hour or less...an overlap of 15-40 bp, with a primer melting temperature greater than 48℃. Both Snapgene and NEB have ...fragments have stable single stranded DNA secondary structure, such as a hairpin or a stem loop (as might be...overlapping region between fragments also better ensures correct assembly order of the fragments as compared...’ exonuclease instead of using the exonuclease feature of T4 DNA polymerase, which must be controlled ... these kits may come at a high price, their manufacturers tout great efficiency and low time commitments... -
Antibodies 101: Fc Effector Functions
TypeBlog Post...constant, or Fc, domain. Sure, we all know that the Fc domain provides structure, determines isotypes, and...does! While the Fc domain’s functions, besides structure and isotype determination, don’t generally affect...sorted into three main effector functions. Figure 1: Fc effector functions in an immune response ...antibody-dependent cellular phagocytosis (ADCP). Figure adapted from van Erp, et al., 2019. Antibody-dependent...description with the Fc domain as only providing structure and isotype determination, remember that it can...Ig Constant Region Effects on Variable Region Structure and Function. Frontiers in Microbiology, 7. https... -
An Addgene Summer Internship
TypeBlog Post...through the La Vida Scholars summer program. I was unsure whether or not I wanted to major in biochemistry..., who let me know in March that I successfully secured an internship at Addgene! I was eager to accept...took into consideration just how busy I was and ensured that my decision deadline would be extended. I ...reached out to Amy with exciting news. I managed to secure a virtual summer program, teaching me the basics...each intern to complete and present on. Figure 1: Addgene's summer interns presenting their capstone...crunch and knew that if we were to restart the procedure we would not have enough time. During the following...from the electrophoresis, my manager and I were unsure if there were any successful clones because the... -
Year of the Camelid: Antibody Style
TypeBlog Post...model and a source of sdAbs (Figure 2) (Xu, et al., 2021). Figure 2: Genetically modified mice...found similar antibodies in llamas and alpacas (Figure 1). At the time, researchers were already on a ...nanobodies (Arbabi-Ghahroudi, 2017)! Figure 1: Comparison of a heavy-chain only antibody and... for in vivo experiments, due to their simple structure sdAbs in research These advantages have contributed...Single-Domain Antibodies: Historical Perspective and Future Outlook. Front Immunol 8:1589. https://doi.org/...mice and llamas neutralize SARS-CoV-2 variants. Nature 595:278–282. https://doi.org/10.1038/s41586-021... -
FastCloning: A Newer, Simpler Cloning Technique
TypeBlog Post...techniques with higher efficiency and simpler procedures have been developed. Some of these include, TA...annealed and ligated in vivo. Detailed FastCloning procedure To start the FastCloning process, the insert and...and the resultant products of the reaction in the figure from Chaokun et al., 2011 to the right. After PCR...isolated from methylation competent E. coli for this procedure to work properly. Directly transform chemically...chemically competent cells with the digested mixture. There is no need for further purification before transformation...vector + insert). You should screen 3-4 colonies to ensure that you find the correct product. Once you find...have a better understanding of the step by step procedure of FastCloning, here are some tips for high efficiency... -
Oh, The Places You Can Go: Careers in Science Communication - Product Development
TypeBlog Post... a couple of lectures in the undergraduate pharmacology course, like one or two lectures a year. And then.... And make sure to subscribe to the Career Channel of the blog so you don’t miss the future posts in this... the first time. I walk[ed them] through their lecture, giving them advice, [and helped] proctor exams...how to design test questions, and how to design lectures. I really built a course from the ground up.” ...careers while in grad school And just for good measure, here’s a few other posts about developing transferable... -
HA Frankenbody, a New Imaging Tool to Visualize Single Molecules and Nascent Peptides
TypeBlog Post...probe for imaging nascent and mature HA-tagged proteins in vivo. Nature Communications, 10(1). PubMed ...fragments (scFvs) (Inbar et al., 1972) are fused to mature fluorophores, and can bind and light up epitope...., 2004). This scFv hybrid provides the probe structure and stability from the scaffold as well as specificity...it is translated quickly by the ribosome. This feature provides HA frankenbody the ability to bind nascent... wide range of protein dynamics in vivo. In the future, this stitching technique could be applied to other...applications: CDR grafting to stable frameworks and structure-based framework engineering. Methods, 34(2), 184... -
Tetbow: Bright Multicolor Labeling for Neuronal Tracing
TypeBlog Post...expression of XFPs is possible by simply introducing a mixture of XFP genes. Stochastic multicolor labeling is...trans-activator Brainbow) (Sakaguchi et al., 2018) (Figure 1). Once introduced, fluorescent proteins were ...AAVs (prepared with Addgene #104110 - #104112) (Figure 2). We’ve also created constructs with containing...Kohl et al., 2014) (Addgene #104106 - #104108) (Figure 3) that can be introduced using in utero electroporation...samples and visualize. For more details on this procedure, find the protocol here. Tips and troubleshooting... al. "Improved tools for the Brainbow toolbox." Nature methods 10.6 (2013): 540. PubMed PMID: 23817127...of fluorescent proteins in the nervous system." Nature 450.7166 (2007): 56. PubMed PMID: 17972876. Kohl... -
Safe Port in a Storm...How Addgene is Weathering the Pandemic
TypeBlog Post...never expected to be in this here and now. Our closure was earlier than most companies. Since the start...around the world mobilized on COVID-19 research, cures, and diagnostics. Almost immediately we began to...receiving packages. So the entire team mobilized to figure out how to deliver when labs finally opened. I...Addgene’s Technology Transfer Team also moved fast to ensure that the majority of deposited materials to study...the dramatic reduction in distribution, we had to figure out a way to maintain our services during the crisis...accelerating research. Yet this was still not enough to ensure we could keep up with demand and keep new projects...scientific sharing of materials for the foreseeable future. ... -
Viral Vectors 101: What is a Virus (and a Viral Vector)?
TypeBlog Post...been developed around how they replicate (Figure 2). Figure 2: Baltimore replication classes. Image credit...molecular biology tools, a very useful trait. Virus structure While all viruses have a genome inside a protein... with an envelope are called enveloped viruses (Figure 1). Like bacteria, only a tiny fraction of viruses...viruses are pathogenic (Balloux & van Dorp, 2017). Figure 1: A non-enveloped virus (left) and an enveloped...packaged in separate plasmids and expressed via cells cultured with the vectors. This allows the viral vectors...of Viral Vectors 101 posts about each type, so be sure to check our blog, or our Viral Vectors 101 eBook... -
Delivery Methods for Generating iPSCs
TypeBlog Post...carte." Nature Reviews Genetics 12, no. 4 (2011): 231-42. PubMed PMID: 21339765. Methods figures were adapted...purify reprogramming proteins. Table 1: Key Features of Different Methods for Generating iPSCs. One...even after many passages. Ban et al developed a temperature sensitive Sendai virus which is removed by culturing...endogenous pluripotency genes (i.e. Oct4) are other measures of reprogramming. If a retrovirus was used, then...field of induced pluripotency: Recent progress and future challenges." Journal of Cellular Physiology 228...pluripotent mouse stem cells by the piggyBac transposon." Nature Methods 6, no. 5 (2009): 363-69. PubMed PMID: 19337237...minicircle vector for deriving human iPS cells." Nature Methods 7, no. 3 (2010): 197-99. PubMed PMID: 20139967... -
"Build Your Plasmid": The Game - Play to Teach
TypeBlog Post...education for future generations. All suggestions, tips and critiques to improve the educational nature of this...in these courses get plenty of theory in their lectures, but it can be difficult to determine how much...hands-on, it will be “brains-on”! I know that even lectures should be “brains-on”, but as much as I try being...have never experienced 100% student engagement. I figured, an engaging card game could help me get the engagement...students to use concepts learned from previous lectures, articles and books. A game where they would use...spurred by this “gamification” will lead to new cures for disease someday! Accessing and modifying BUILD... -
The Importance of High Titer for AAV Transductions
TypeBlog Post...make sure to rinse off the surface of the filter membrane with the surrounding solution to ensure excess...concentration to avoid over-diluting, and make sure to remeasure your titer after diluting to confirm. Luke...drastically with lower titers. As you can see in figure 2, the expression from the 5x1011 titer was essentially... in a roughly 6-fold increase in expression [3, Figure 2]. Note how expression increases exponentially...additional best practices. Keep your cells happy - Make sure your cells are as healthy as can be to prepare them... -
Hot Plasmids - September 2019 - CRISPR, Auxin Inducible Degradation, MerMAID Channelrhodopsins, and Genome Looping
TypeBlog Post...requires an NGG PAM to recognize the target. Osamu Nureki’s lab engineered SpCas9 (SpCas9-NG) with relaxed... with high precision - a valuable optogenetics feature when studying neuronal activity. The researchers...MerMAIDs plasmids at Addgene Opperman J et al., Nature Communications, 2019. PubMed PMID: 31346176. Using... of loops. These loops not only provide a 3-D structure for packing genomic DNA into nuclei, but are also...that heterodimerizes with CIBN upon blue light exposure (see Fig 1*). When the group targeted the enhancer...system promises to be a better model for the dynamic nature of genomic looping due to it’s briefer time scale...scale and its inducible and reversible nature. Find the LADL plasmids at Addgene Kim et al., Nat Methods... -
Reagent Repositories Are Speeding up Science During the Pandemic
TypeBlog Post...be available from their original sources. Figure 1: Biological repositories that distribute mouse... such example is cell lines. The American Type Culture Collection (ATCC) is a private, nonprofit repository... community. Addgene was awarded a Fast Grant to ensure that the scientific community will continue having...have already been requested from Addgene. Figure 2: Total COVID-19 plasmids requested from Addgene...making materials available rapidly to scientists (Nature Biotechnology 2020). The continued success of repositories... repositories, during the pandemic and in the future, depends on support from the scientific community...fundamental part of the scientific research infrastructure. References Chu H, Chan JF-W, Yuen TT-T, ... -
25 Work From Home Tips for Scientists
TypeBlog Post...difficult if your work is based in the lab. If you’re unsure what to do during this period, check out these ... Organize data that you already collected into figures for papers or presentations. Learn a new skill ...novel findings. Most Micropublications contain one figure. If you aren’t there yet, write introductions to...while. Getting started early on introductions and literature reviews could make the months leading up to your...about reproducibility best practices Support your future experiments and other researchers by implementing...Also consider using this framework to design your future experiments. Use Addgene’s AAV Data Hub. You can...can search the AAV Data Hub for tools to use in future experiments. If you’ve used Addgene’s AAV tools... -
Fluorescent Protein Travel Awards - FLiPs and Fluorescent Protein Biosensors
TypeBlog Post...proteins and the potential for their work to enable future discoveries. Read on to learn more about Xin and...keep checking back in with the Addgene blog for future award opportunities. Xin Zhou: Fluorescent Light-inducible...active site. In these fusions, ultraviolet light exposure caused oligomerization of the Dronpa domains thereby...active site and shutting off the enzyme. Later exposure to cyan light stopped Dronpa oligomerization and...active site and still block enzyme function upon exposure to ultraviolet light. Previous iterations of FLiPs... needed an efficient and cost-effective way to measure the production of HMOs. Current HPLC-MS and fluorophore-based...ACS meeting. She hopes these biosensors and her future work with HMOs will enable researchers to engineer... -
Predicting Adverse Reactions to Monoclonal Antibody Drugs
TypeBlog Post...Using Existing in silico Algorithm Infrastructure and a Vision for Future Enhancements. Frontiers in drug...immunogenicity score (Mattei et.al., 2022). Figure 1: Generation of immunogenicity scores by predictive...individually-specific factors, such as previous exposures to that specific antigen, pre-existing conditions...factors that in silico prediction algorithms fail to capture. In vitro evaluation of therapeutic immunogenicity...various components of the immune system. Figure 2: In-vitro models for immunogenicity prediction...and the advancement of precision medicine in the future. Madhura Acharya is a former co-op and current... -
How to Lead a Great Meeting
TypeBlog Post...from last meeting. Use some positive peer pressure to make sure everyone completes their assigned items ... on details that do not yet need to be decided. Figure out what you need to accomplish to get to the next...toward a solution. At the end of the meeting, make sure to thank everyone for their participation and offer... are working on. Building this into the agenda ensures that everyone gets a chance to talk and less vocal... so will the length of your group meetings. Make sure to keep them manageable. At Addgene, teams can add...all-company meetings, monthly still works best. Figure out what works for you for each of your meeting... -
Plasmids 101: Inducible Promoters
TypeBlog Post...synthetic) pFZ19 (yellow flame) Temperature inducible promoters Temperature sensitive expression systems ... expression at regular temperatures but can be induced by heat or cold exposure. Examples include the ...Types of inducible promoters Chemical agents, temperature, and light are all examples of factors that can...which a gene of choice is only expressed following exposure to a brief heat shock. In the case of Hsp70, the...since expression can be repressed by glucose. Temperature inducible promoters are also known for their ... -
Targeted Mutagenesis with EvolvR
TypeBlog Post...PACE) method requires constant turbidity of the culture, so bacteria must be grown in a turbidostat. ...activity degrades the displaced strand. Figure 1: EvolvR consists of an error-prone polymerase...by 120-fold over background. Due to its modular nature, the Dueber Lab created a few versions of EvolvR... more than one genomic site for mutagenesis, a feature which they used to generate bacteria resistant ...at a user-defined loci in bacteria. Its modular nature provides versatility in defining the mutational...diversification of all nucleotides in a tunable window." Nature 560.7717 (2018): 248. PubMed PMID: 30069054. Sadanand..., Saheli. "EvolvR-ing to targeted mutagenesis." Nature biotechnology 36.9 (2018): 819. Additional resources... -
Fluorescent CRISPR Reporters: SRIRACCHA and GEmCherry2
TypeBlog Post... base-pair editing CRISPR reporters in the near future. SRIRACCHA (stable, but reversible, integrated...reporter into the genome of mammalian cells. Figure 1: The SRIRACCHA reporter construct. Image from... for assessing CRISPR/Cas9 activity Guide RNA structure and the site in the genome you are trying to target...Thus it is essential to identify the best sgRNA to ensure success in your CRISPR experiments. But how? There... fluorescence and in-frame fluorescence. Figure 2: The GEmCherry reporter. Image from Højland Knudsen...FACs sorting, confirming yet again that sgRNA structure and genomic recognition sites play a large role... for editing, regulating and targeting genomes. Nature Biotechnology 32:347–355 . https://doi.org/10.1038... -
Antibodies 101: Isotypes
TypeBlog Post...surface of most immature B cells, its function is unknown. It has a monomer structure with a valency of... region: IgM, IgD, IgG, IgE, and IgA. Figure 1: Diagram of an antibody labeled with Fc, Fab,...antigen of interest. Isotype controls are used to make sure the staining you see is due to target-specific antibody...region length. Now for some essential isotype nomenclature. Antibody heavy chain proteins as well as the...cells begin by expressing IgM. IgM has a pentamer structure, which means each IgM molecule has a binding capacity... for IgM, IgD, and IgG are deleted. Figure 2: Isotype switching requires DNA recombination... -
Plasmids 101: Sequence and Ligation Independent Cloning (SLIC)
TypeBlog Post...have stable ssDNA secondary structure — for example, the stem-loop structure of transcriptional terminators...higher temperature at which Gibson assembly takes place may limit formation of secondary structures at the...with 5′ overhangs generated either by annealing a mixture of products or from incomplete PCR — although higher...effective with as little as 3 ng of DNA!) Figure 1: Schematic of SLIC. To start the SLIC cloning...successful, but at a lower efficiency (~20%). Figure 2: Schematic of multicomponent assembly with SLIC... -
A Practical Guide to Optimizing AAV DIO and FLEx Vector Expression
TypeBlog Post...sandwiched between 2 loxp sites and is excised by Cre (Figure 1). This results in one loxp site and one lox2272...Since loxp and lox2272 can not recombine, this ensures that the transgene is no longer able to flip back...the cause of this spurious expression? Figure 1. Cre-recombinase binds to either pair of lox...orientation preventing the transgene from reverting. Figure created with BioRender.com Causes of recombination...to flank the transgenes (non-homologous pairs) (Figure 2.). They found that almost all off-target expression... to exercise caution when using them. Figure 2. Schematic diagram showing the mechanism of spontaneous...reduced reversion and less off-target expression. Figure created with BioRender.com Strategies for... -
Important Considerations When Using AAVs
TypeBlog Post...University of Manitoba. Location, Location, Location! Failure to Plan (for Storage) Is Planning to Fail Patience...Patience Is Bitter but Its Fruit Is Sweet The Future? I knew little about adeno-associated Viral Vectors...sufficient to overcome the transport issues. 2. Failure to plan (for storage) Is planning to fail Freeze...not take much time at all. Much of the previous literature using AAVs for DREADD delivery indicates ~7-21...to use AAV constructs with self-complementing structure (scAAV) (7). As single stranded DNA viruses, AAVs...from ~4.8 kB [8] to ~2.3 kB [9]). 4. The Future What new types of research may be enabled by the...experiments, a group of researchers has identified this feature of AAVs as a new tool for neuroanatomical tracing... -
Hot Plasmids - March 2020 - base editors, GEVI, MoClo, and optogenetics
TypeBlog Post... a native peptide bond at the split site. Figure 1: The base editor is split into two plasmids and...the split base editors at Addgene. Levy et al., Nature Biomedical Engineering, 2020. PubMed PMID: 31937940...in higher quenching of mScarlet emission. Figure 2: Ace-mScarlet is a fusion between the voltage-sensitive...synthetic biology tools for cyanobacteria. Figure 3: Assembly of plasmids using the Cyanogate Kit...reducing Cre toxicity in long-term experiments. Figure 4: The C-terminus of Cre (CreC) and the N-terminus...(PCB), is required for PhyBΔ to be functional. Exposure to red light induces PhyBΔ and PIF6APB binding...This novel tool is practical in cell and organ culture, as well as cell lineage studies. Eisenhoffer and... -
Announcing the Winners of the 2021 Michael Davidson and Roger Tsien Commemorative Conference Awards
TypeBlog Post...Glutamate sensing reporters Abhi Aggarwal is a postbaccalaureate research technician in Kaspar Podgorski’s ...expression and trafficking of these biosensors. Figure 1: Schematic of iGluSnFR3 (left). GluSnFR3 in pMinDisplay... domain), in electroporated in rat hippocampal cultured neurons, imaged 14 days post-transfection, excited...happen inside the cell,” says Pedre Pérez. Figure 2: Micrographs of the biosensor expressed in the...from opioid use disorder,” says Hubbard. Figure 3: 20x confocal image of the periaqueductal gray...response to light touch in mechanical allodynia. Figure 4: While Qiu’s work on the PV neurons is in progress...calcium, and membrane voltage,” says Tian. Figure 5: Citrine-tagged voltage indicator expressed in... -
CRISPR 101: Cas9 vs. The Other Cas(s)
TypeBlog Post...engineering enzymes, each with their own unique features and quirks. Here, we will review the genome engineering.... Dozens of variants exist with unique cutting features and evolved PAM sites, making Cas9 an adaptable...PAM does not require any G’s or C’s. One curious feature of this Cas is that once it is engaged by its target...target, it will non-specifically cut ssDNA. This feature is shared by other Cas enzymes outlined below as... proteins should not be overlooked. The unique features and targeting abilities of the other Cas family...Janice, et. al. Programmed DNA destruction by miniature CRISPR-Cas14 enzymes. Science, 362(6416): 839-...with the single-protein CRISPR effector Cas7-11. Nature, 597, 720-725 (2021). 10.1038/s41586-021-03886-... -
Gendered Innovations: Why Does Sex of the Cell Matter?
TypeBlog Post...the analysis did find 263,000 more osteoporotic fractures. The overall economic savings to the US healthcare... Unfortunately, it also meant that, by the very nature of the way the experiments were performed, they...and cell research. Using cells from both sexes ensures that the diagnostics and therapeutic interventions...recent years, and you can see a summary of this literature in our health and medicine checklist. A common...not analyzed) may harm humans or contribute to failures in drug development – costs far greater than those...doing the research correctly from the get go. The future of sex and gender in research There is much work...Blog Learn How Scientists Are Trying to Shape the Future of Research Learn How Notions of Scientific Impact... -
Plasmids 101: Modular Cloning Applications and Kits
TypeBlog Post...individual parts are reusable, saving time and money on future assemblies. If you are new to MoClo, give our MoClo...synthesis of these molecules. To make large amounts of pure product in an affordable way, researchers test many...your yeast experimental goals are more general in nature, or you aren’t planning on using K. phaffii, then...proteins within the mitochondrial matrix. Figure 1: A chart with MoClo kit recommendations for different...2023). The Plant Parts II kit has a focus on infrastructure with shuttle vectors, several delivery systems...targets or multiple sgRNAs against the same target to ensure efficient cutting. Beyond sgRNAs, MoClo can also...convolute the results of these experiments. The modular nature of the Fragmid system allows for direct comparisons... -
A Primer on Optogenetics: Introduction and Opsin Delivery
TypeBlog Post...Behavioral experimentation I’ll discuss some of the key features of each of these steps. Today we’ll discuss selection...relies on identification of the bregma and lambda sutures and subsequent determination of the proper coordinates... your brain region of interest (as shown in the figure below). Since most of the precision of optogenetics...circuits underlying brain disease in animal models. Nature reviews Neuroscience. 2012;13(4):251-66. doi: 10.1038...of neuroscience. 2011;34:389-412. doi: 10.1146/annurev-neuro-061010-113817. PMID: 21692661. 3. Bernstein...direct comparative analysis of microbial opsins. Nature methods. 2012;9(2):159-72. doi: 10.1038/nmeth.1808...mice for light-induced activation and silencing. Nature neuroscience. 2012;15(5):793-802. doi: 10.1038/... -
Adenoviral Vector Production and Troubleshooting
TypeBlog Post...(ITR) present at both ends. Figure 1: A) The structure of an adenovirus: the virion is ~ 100nm...genomes/mL) can be measured by: Optical density: particle concentration is measured by looking at absorbance... construct from step #1 and allowed to stay in culture for up to 20 additional days at which time the ...recombinant adenoviruses using the AdEasy system." Nature protocols 2.5 (2007): 1236. PubMed PMID: 17546019...production of high-capacity adenoviral vectors." Nature protocols 4.4 (2009): 547. PubMed PMID: 19373227... -
Pathways Over Time Plasmids Engage Students in Functional Genomics Research
TypeBlog Post...Met protein complementation. In the procedure diagrammed in Figure 3, students first transform the S. ...available (6). Methionine synthesis in S. cerevisiae (Figure 1) occurs through a well-characterized pathway ... the deletion). Find the Plasmids Here Plasmid features enable multiple student experiments We used TOPO...coding sequences for ten different MET/Met genes (Figure 1) from the two yeast species into the pYES2.1/... controlled by the GAL1 promoter. The cloning procedure adds both V5 and His6 epitope tags to the C-termini...expression by western blotting in other experiments (Figure 2). Complementation reveals conservation of function... -
Quickest Way to Deposit Plasmids: The Deposit Spreadsheet
TypeBlog Post...office or other authorized office directly to make sure the deposit agreement/MTA is taken care of and, ...Deposit” and “Download Deposit Spreadsheet” (see Figure 1). Please read our “How to Deposit Your Plasmids...thorough guide to our online data entry process. Figure 1: Begin the deposit process by clicking “Submit...Required columns are shown in red in the spreadsheet (Figure 2) and are described in Table 1. Some cells have...Growth Temp Choose from 30 °C, 37 °C, or room temperature. Growth Strain Please indicate which growth...Filling out and sending the deposit spreadsheet Figure 2: Example of the deposit spreadsheet showing the...update the spreadsheet every so often and this ensures you are using our most up-to-date version! We hope... -
CRISPR in the Clinic
TypeBlog Post...focus was on editing animal models of disease and cultured cells. For example, in 2013, Jinsong Li and colleagues...When all was said and done, the researchers had cured 24 mice of their disease. Meanwhile, Hans Clevers...significant progress in clinical trials. Figure 1: Types of delivery and editing strategies for...success rate in clearing misfolded protein levels as measured in the blood. More information is expected soon...blindness, and diabetes. Directions and obstacles for future CRISPR therapies CRISPR technology is rapidly evolving...strides since we first wrote this blog post. The future success of CRISPR in the clinical will rely on ...MA, Berkhout B, Herrera-Carrillo E. A CRISPR-Cas Cure for HIV/AIDS. Int J Mol Sci. 2023 Jan 13;24(2):1563... -
Plasmids 101: The Wide World of Natural Plasmids
TypeBlog Post...we’re really borrowing these tools from Mother Nature’s toolbox. Natural plasmids, also called environmental...the basis of many molecular biology tools! Figure 1: Common functions of natural plasmids. Created... to survive where others can’t. This ability to endure a harsh environment is distinct from the benefit...new types of plasmids without clear analogues in nature. For example, helper plasmids were developed to... To learn more about some other common plasmid features, such as origins of replication and promoters,... blog as scientists continue to explore Mother Nature’s toolbox for new and exciting molecular technologies...Resources References Demanèche, S., Bertolla, F., Buret, F., Nalin, R., Sailland, A., Auriol, P., Vogel,... -
Making CRISPR Plasmids Using Fragmid
TypeBlog Post...Did you say… easier? Fragmid’s modular assembly structure takes a lot of the design work out of the plasmid...Fragmid components on the Fragmid website. Figure 1: (Top) Schematic overview and timeline of the...schematized. Sizes of fragments are not to scale. Figure and caption from McGee et al., 2024, used under...designing a CRISPR vector the Fragmid way! Figure 1: Selecting your vector type on the Fragmid website...website. In step one, you’ll select the features of your vector, which are: Organism (Mammalian...mechanism (KO, CRISPRa, CRISPRi, editing) Figure 2: Selecting module fragments on the Fragmid website...want? You can make your own Fragmid components! Ensure your backbone and genes contain only the Bbsl cut... -
xCas9: Engineering a CRISPR Variant with PAM Flexibility
TypeBlog Post...compatibility and high DNA specificity." Nature (2018) doi: 10.1038/nature26155 PubMed PMID: 29512652 Plasmids...loci or genomes. Cas9s from other species, like S. aureus and N. meningitidis require different PAM sites...first restored catalytic residues D10 and H840. To ensure that the clones were capable of cleavage, they ...fused to third generation cytidine base editor architecture (BE3) slightly improves NGG PAM editing efficiency...efficiencies (edit frequency in cell population measured with NGS) are shown as percentages, with fold ...lot we still don’t know about xCas9. “I’m not 100% sure xCas9 is going to be flat out better than SpCas9... -
Adenoviral Delivery of CRISPR/Cas9 Aims to Expand Genome Editing to Primary Cells
TypeBlog Post...the CRISPR/Cas9 system. Nature 516:423–427 . https://doi.org/10.1038/nature13902 Maggio I, Holkers M, Liu... the target cells (Beatty et al., 2012). These features make AdV an attractive candidate for in vivo delivery...genome editing machinery such as CRISPR-Cas. Figure 1: Schematic of targeted gene knock-out (left) ...Gonçalves' lab found in a second paper published in Nature Methods the same year that delivering RNA-guided...double-stranded AdV genomes. Such protein-DNA structures presumably reduce the likelihood that donor DNA... that advantages of AdVs include their episomal nature and very efficient introduction of DNA into therapeutically... -
Viral Vectors 101: Voltage Indicators
TypeBlog Post...electrical potential. Thankfully, there is a tool to measure these electrical events! Voltage indicators are...They can be targeted to the plasma membrane to measure membrane potential and can also be directed to ...applications such as in vivo tissue imaging. Figure 1: Ace-mScarlet is a fusion between the voltage-sensitive...depending on your experimental system. Figure 2: General overview of chemigenetic tools. A genetically...vitro and a small molecule is added exogenously to measure a phenotypic response in the form of fluorescence...Indicators As previously mentioned, cellular voltage is measured at the cell membrane, and this voltage is particularly...has you covered. Happy voltage sensing! Figure 3: Components of the types of voltage indicators... -
The AAVantages of AAV in CRISPR Screens
TypeBlog Post...sequencing (NGS) to identify genes of interest. Figure 1: Overview of in vitro AAV CRISPR screens. Created... capsids, or serotypes, have been identified in nature, while many more have been engineered in labs. ...improve infection rates in your experiment. Figure 2: Visual representation of common AAV serotypes...smaller Cas9 ortholog like SaCas9. You could even venture away from the comfort of Cas9, and opt for a completely...design and execution of CRISPR in vivo screens. Nature Protocols, 17(9), 1903–1925. https://doi.org/10.1038...vector integration into CRISPR-induced DNA breaks. Nature Communications, 10(1). https://doi.org/10.1038/... linkage analysis with in vivo AAV-Perturb-seq. Nature, 622(7982), 367–375. https://doi.org/10.1038/s41586... -
Anatomy of a Plasmid Page at Addgene
TypeBlog Post... to quickly check out the plasmid's structural features and see if I can easily clone my gene into it?...plasmid map based off of the plasmid sequence and feature information given by our depositors. Many depositors...plasmids are sent as bacterial stabs at room temperature. Core of the plasmid page - Core of the plasmid...), antibiotic resistance, and optimal growth temperature are listed, as well as the name of the strain... Citing this Plasmid: This is a relatively new feature of our plasmid pages, and provides a list of publications...our blog post) for more information about this feature!). This means you can see which labs have already...the Addgene Blog Read about Our New Citations Feature Check out Our Walkthrough of the Deposit Process... -
CRISPR 101: Mammalian Expression Systems and Delivery Methods
TypeBlog Post...exclusively to in vitro cell culture. The user should review the current literature about their preferred model...single-stranded DNA oligonucleotide, so you will need to make sure your expression system and delivery methods are ...system, a good first step would be to consult the literature to see if anyone has published a protocol that...in in vitro transcription reactions to generate mature Cas9 mRNA and gRNA. RNA is delivered to target ...different methods, so we've summarized some key features of common delivery methods below: Chemical transfection...Resources on the Addgene Blog Check out our CRISPR Featured Topic Page Learn about CRISPR Delivery Using Ribonucleoproteins... -
Genome-wide Screening Using CRISPR
TypeBlog Post.... Figure 1: Like this jar of jellybeans, a pooled CRISPR library is a complex mixture. Pooled libraries...experimental system are absolutely necessary to ensure that you select the correct CRISPR library. Choosing...concentration that is sufficient to generate lentivirus. Be sure to use next-generation sequencing to check the quality...cells gain resistance to drugs and can identify future therapeutic targets for diseases causing uncontrolled...uncontrolled cell growth, such as cancer. Figure 2: The CRISPR library must be amplified (A) to be ...the screen should be independently validated to ensure that the desired modification produces the phenotype... -
Don’t FRET: Bimolecular Fluorescence Complementation Makes Visualizing Protein-Protein Interactions Easy
TypeBlog Post...re tethered to bring them into close proximity (Figure 1). Formation of the complete FP results in a fluorescent...can be detected by fluorescence microscopy. Figure 1: How BiFC works. A split FP (e.g., yellow fluorescent...localization of the studied PIPs. The straightforward nature of BiFC also makes it easier to generate a large...fragments and, preferably, some information about the structures of the tested PIPs. Many split FPs have been ...BiFC experiments only require that you image and measure the fluorescence of a single FP. Your control construct...one another — which means it cannot be used to measure the dissociation of PIPs. Thus, whereas BiFC is...fluorescence complementation (BiFC): A 5-year update and future perspectives. Biotech 53. https://doi.org/10.2144... -
An Introduction to Adenovirus
TypeBlog Post...causing a lack of exposure, a lack of immunity, and then finally a synchronized exposure under these conditions...conditions once the measures were lifted (Servellita et al., 2023). This anecdote goes toward saying that...certain contexts (Bauzon et al., 2003). Figure 1: The adenovirus life cycle. Image reused from...31749409. Harrach, B. (2014). Adenoviruses: General Features. In Reference Module in Biomedical Sciences. Elsevier... Undergoing Spontaneous Degeneration in Tissue Culture. Proc Soc Exp Biol Med. 84(3), 570–573. https:/...type 2 in US children with acute severe hepatitis. Nature, 617(7961), 574–580. https://doi.org/10.1038/s41586... -
Fluorescent Proteins 101: Green Fluorescent Protein (GFP)
TypeBlog Post...center of the structure, shielded from quenching by aqueous solvent. This tightly-packed structure explains...Fluorescent Protein (GFP) has likely existed in creatures such as jellyfish for millions of years; however...while still maintaining fluorescence. The protein structure, first reported in 1996, is an eleven β-sheet-...yield for BFP Y145A and H148D Stabilizes the structure of Cerulean derivatives F99S, M153T, V163A Improves...Optogenetics: Scientists can use light to detect, measure, and control molecular signals, cells, and groups...This is a type of flow cytometry that separates mixtures of cells into distinct populations based on fluorescent... -
Podcast: A Malawian Professor's Path to Biotech Research
TypeBlog Post...Kwapata now works as a lecturer in molecular genetics and biotechnology for Horticulture and Forest Crops at... at the Lilongwe University of Agriculture and Natural Resources. He recently received an award from nonprofit...Kingdom ended up working in the life sciences and agriculture 5:47-9:35 : Kingdom's biotechnology research ...transition back to Malawi and Lilongwe University of Agriculture and Natural Resources 10:30-11:41 : Kingdom on...Seeding Lab's Work with Lilongwe Univeristy of Agriculture and Natural Resources Watch Dr. Kwapata's Speech...