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Showing: 81 - 100 of 621 results
  1. Quick Guide to All Things Lentivirus

    Type
    Blog Post
    Published
    March 21, 2017, 2:30 p.m.
    ...family including human immunodeficiency virus type-1 (HIV-1), can infect both dividing and non-dividing cells...have been devoted to develop efficient and safe HIV-1-derived lentiviral vectors due to their ability to...lentiviral vectors consisted of three plasmids encoding 1) the lentiviral vector genome which was composed of...desired gene (transfer vector plasmid), 2) the HIV-1 genome containing all viral genes with the exception...generation because this vector requires only three HIV-1 genes (gag, pol, and rev) for production. Third generation...several protocols that have been described (protocol 1, protocol 2, protocol 3) to find the one that will...to additional protocols and plasmids.  References 1. Miller, A. DUSTY, and C. A. R. O. L. Buttimore. "...
  2. SciComm with the Experts at Science in the News Part 1

    Type
    Blog Post
    Published
    March 16, 2017, 1:06 p.m.
    ...Science Communication Conversation in Science Communication The Purpose of Science Communication #1 Mistake...think about communicating science. Listen to the interview with Science in the News, Part 1 Podcast breakdown...supporters of science communication. To help you think about ways to effectively communicate your science, we...News at Harvard University. Effective science communication is required to promote public support for research... organization that works to promote science communication. Science in the News hosts a podcast, seminars...That’s right, #ActualLivingScientists, eager to communicate their science. In this first half of our two-...Mistake Scientists Make when Communicating with Non-Scientists How to Approach Different Audiences Listen...
  3. Technical Design of a Western Blot

    Type
    Blog Post
    Published
    Aug. 22, 2024, 1:15 p.m.
    ...Tris-tricine 2.5–40 kDa Tris-tricine 30 V, 1 hour or 100 V, 1–2 hours Good separation, quality, and stability...lot to cover, so let's dive in!      Figure 1: The technical decisions to make when designing a ...assay. The most common options are 4 °C overnight or 1–2 hours at room temperature (RT). Most people choose...overnight at 4 °C and their secondary antibody for 1–2 hrs at room temperature, which allows them to reduce...weight of the proteins you’re interested in. Table 1 lists the most common types of gels for SDS-PAGE running...gel chemistry and/or specialty gel options. Table 1: Types of gels  Gel Type Protein sizes Running... Tris-glycine 6–400 kDa Tris-glycine 100 V, 1–2 hours Easy and cheap to handcast Short shelf-life...
  4. Getting to Know Expansion Microscopy

    Type
    Blog Post
    Published
    June 20, 2023, 1:15 p.m.
    ...protocols. A typical ExM protocol (Fig. 1) follows this structure: Step 1: fix (and maybe label) your sample...microscopy. Nat Biotechnol 1–12. https://doi.org/10.1038/s41587-022-01546-1  Mikhaylova M, Cloin BMC, ...just adding water.)  Step 5: Image   Figure 1: The ExM process allows you to physically magnify ...16:71–74. https://doi.org/10.1038/s41592-018-0238-1  Klimas A, Gallagher BR, Wijesekara P, et al (2023...with an abundance of protocols and examples of applications from across disciplines now available. In this...experiment or evaluating ExM images in a new publication.         Why Expansion Microscopy?  Traditional...microscopes sounds great, right? But there is always a catch - some limitation of the technique that users should...
  5. Plasmids 101: Gateway Cloning

    Type
    Blog Post
    Published
    Jan. 12, 2017, 3:30 p.m.
    ...recombination sites (attL-left- and attR-right-, Figure 1). Under certain conditions, the attL and attR sites...regeneration of attP and attB sites.   Figure 1: Lambda phage integration and excision reactions. ...expression of the human KRAS gene in mammalian cells. STEP 1: Generate an Entry Clone There are a few different...could use a vector like pLenti CMV Puro DEST (w118-1) or the doxycycline-inducible pLIX_403. The chosen...the generation of the expression construct in only 1 day, as opposed to 2+ days with traditional restriction... Find Gateway cloning plasmids here! References 1. Chee JY, Chin CF (2015) Gateway Cloning Technology...attP sites of the donor vector. This reaction is catalyzed by the BP Clonase enzyme mix and generates the...
  6. Viral Vectors 101: What is a Virus (and a Viral Vector)?

    Type
    Blog Post
    Published
    Aug. 18, 2023, 4:15 p.m.
    ...Virus Replication. Essential Human Virology, 49. https://doi.org/10.1016/B978-0-12-800947-5.00004-1 Taylor... an envelope are called enveloped viruses (Figure 1). Like bacteria, only a tiny fraction of viruses are...are pathogenic (Balloux & van Dorp, 2017). Figure 1: A non-enveloped virus (left) and an enveloped virus...create far safer viral vectors that can be used in BSL-1 or BSL-2 labs. Viral vectors are viruses that have...methods of replication. In fact, an entire classification scheme, known as the Baltimore replication classes...that in a bit! Viral genomes and replication When it comes to replication, viruses tend to march to the ...developed around how they replicate (Figure 2). Figure 2: Baltimore replication classes. Image credit: ...
  7. Click Biology: How to Click and Play to Explore Biology

    Type
    Blog Post
    Published
    Oct. 21, 2025, 1:15 p.m.
    ... gp41-1 Split inteins A small, fast split intein SpyTag003/SpyCatcher003 SpyTag/SpyCatcher Rapid covalent...the best performance in the most contexts (Figure 1). Together the features with optimal biological performance...described as Click Biology (Howarth, 2025). Figure 1: Modular assembly tools, alongside criteria for Click...tools can be found in Addgene's repository (Table 1). Figure 2: Adding function to My Favorite ...coupling. Created with BioRender.com.   Table 1: A handful of Click Biology tools available at Addgene...peptide (SpyTag) and protein (SpyCatcher) SnoopTag/SnoopCatcher SpyTag/SpyCatcher Rapid covalent bond formation...SnoopTag) and protein (SnoopCatcher); no cross-reaction with SpyTag/SpyCatcher, allows for iterative expansion...
  8. Viral Vectors 101: Virus Safety

    Type
    Blog Post
    Published
    June 22, 2023, 1:15 p.m.
    ...including yourself as the researcher.   Figure 1: Separation of retroviral packaging components onto distinct...these reasons, AAV is usually classified as a BSL-1 safety level. Adenovirus is similar to AAV in that...lab coats are either recommended or required in BSL-1 and required in BSL-2 labs. When working with lentivirus...required whenever there’s a splash or spray risk in BSL-1. In BSL-2 labs, eye protection is required any time...isopropyl alcohol, 0.5% peracetic acid, 10% bleach, or 1% iodine are useful. Some organizations or cities may...host genome, the virus is replication incompetent, meaning it can’t replicate and continue the infection... tools, thought was given on how to keep the replication of virus and its infectivity in check. Engineering...
  9. An Interview with Connie Cepko - Gene Therapy, Plasmid Tools and Insights to Success

    Type
    Blog Post
    Published
    Dec. 8, 2015, 3:30 p.m.
    ... Podcast breakdown: (Time : Topic) 0:00-1:00 : Introduction 1:01-9:04 : What got Professor Cepko Interested... producer for the Addgene Podcast.     References 1.Tang, Jonathan C.Y., et al. “A nanobody-based system... PMCID: PMC4096992. Find plasmids from this publication at Addgene. 2. Tang, Jonathan C.Y., et al. “...PubMed PMID: 26258682. Find plasmids from this publication at Addgene. Resources on the Addgene Blog Read...
  10. Sleeping Beauty Awakens for Genome Engineering

    Type
    Blog Post
    Published
    June 30, 2015, 2 p.m.
    ...comprised of 2 components: 1) an SB transposase, the enzyme required for catalysis of transposition; and 2...also important for social and regulatory reasons. 1.) The transposon consists of a mirrored set of inverted...likely to grow in the coming decades.  References 1. Kowarz E, et al. Optimized Sleeping Beauty transposons...T cells to target CD19. Immunol Rev. 2014 Jan;257(1):181-90. doi: 10.1111/imr.12137. PubMed. Find the ... Specifically, viruses are able to infect and replicate in host cells, but they are susceptible to cells... though not all, of these defenses. For some applications of genome engineering - such as certain forms...to integrate. Additionally, the TA sequence is duplicated near the gene of interest insertion site.   The...
  11. High Complexity Golden Gate Assembly with NEB’s DAD

    Type
    Blog Post
    Published
    Aug. 1, 2023, 1:15 p.m.
    ...reactions. (Need a refresher? The five rules are: (1) don’t use the same overhang twice; (2) avoid palindromes...Gate) pot (Pryor et al., 2022).     Figure 1: Workflow for high complexity Golden Gate Assemblies...different enzymes and cycling conditions (see Table 1).   Enzyme Temperature Incubation time/cycling...cycling Overhang length T4 DNA ligase 25 °C 1 hour 3-base or 4-base T4 DNA ligase 25 °C ...hours 3-base or 4-base T4 DNA ligase 37 °C 1 hour 3-base or 4-base T4 DNA ligase 37 °C ...Ligase MM 37-16 °C cycling 3-base Table 1: Enzyme and cycling conditions available in DAD tools...assemblies are possible, the two sets of data together indicate that 35-pieces is a reasonable upper limit for...
  12. Fluorescent Tagging of Endogenous Genes with SapTrap

    Type
    Blog Post
    Published
    Oct. 12, 2017, 2:26 p.m.
    ... 5’ and 3’ homology arm repair template (Fig. 1, Step 1). There is no need for PCR or cloning, as digestion...selectable marker, and connector to be released (Fig. 1, Step 2-3). Since donor plasmids of the same type ...correctly assembles the final targeting vector (Fig. 1, Step 4), and co-injection of the targeting vector...human cells. To use CRISPaint, users need 3 vectors:  1) a gRNA vector that targets the gene of interest, ... Tagging with Short Homology Donors.” Cell Rep.15(1) (2016):210-8. PubMed PMID: 27052166. Kunzelmann,...Toolkit for High-Throughput CRISPR/Cas9 Gene Modification in Caenorhabditis elegans.” Genetics. 202(4)...
  13. Plasmids 101: FLEx Vectors

    Type
    Blog Post
    Published
    April 28, 2016, 2:30 p.m.
    ...coding sequence in the antisense orientation (Figure 1, top). The entire DNA cassette would be flanked by...include both Cre and FLP recombinases.   Figure 1 (modified from Schnutgen et al. Nat Biotech 2003):...identical sites on one end of the DNA fragment (Figure 1, middle). A second recombination event then excises...between the identical loxP or lox511 sites (Figure 1, bottom). Since only one loxP and lox511 site will...genOway press release for more information. References: 1. Schnütgen F, Doerflinger N, Calléja C, Wendling O...sites directs the Cre recombinase to invert, translocate, or excise a DNA fragment. The availability of... the function of various point mutations and truncations in the absence of the endogenous gene. Spatio-temporal...
  14. Twenty Years of Sharing: Expanding Accessibility

    Type
    Blog Post
    Published
    Nov. 21, 2024, 10:47 p.m.
    ...experiment.     Table 1: Most popular guides, protocols, and collections of 2023. Educational Resource Top...visitors in 218 countries. In Table 1, you can see our most popular educational resources for each type of resource...our repository to an amazing 111 countries (Figure 1)! But while we were making the materials available...accessibility varied country to country.   Figure 1: Number of countries Addgene distributes to per year...date, we have partnered with six distributors (Table 1), in China, Korea, Japan, Brazil, India, and Mexico... execute a step can provide needed clarity (Table 1). Our most popular video, however, is “What is a Plasmid...logistical barriers, allowing people to access a wide catalog of plasmids from all over the world. This idea,...
  15. Adeno-associated Viruses (AAVs) for Genome Editing

    Type
    Blog Post
    Published
    March 27, 2018, 1:32 p.m.
    ...infection, gene targeting vectors with relatively short (1 kb) homology arms underwent homologous recombination...sequences of interest to cells with efficiencies of 1-40% after G418 selection (Kohli et al 2004, Kim et...with polylinkers for the addition of gene-specific 1 kb homology arms flanking a FLOXed neoR gene. pAAV-SEPT-Acceptor...since it routinely generates knockin efficiencies of 1-40% with G418-selected clones. However, there are ...efficiency of gene editing is occasionally less than 1%, and virtually never exceeds 40%. While this is comparable...gene inactivation in human cancer.     References 1. Russell, David W., and Roll K. Hirata. "Human gene...gene at once. Therefore, applications that require simultaneous modification of all alleles of a gene,...
  16. PiggyBac-ing Through the Genome Editing Field

    Type
    Blog Post
    Published
    May 31, 2016, 3:30 p.m.
    ...Correct Path.,” J. stem cell Regen. Biol., vol. 1, no. 1, Jan. PubMed PMID: 26702451. PubMed Central PMCID...known upper limit [1]. The piggyBac™ technology can be used for numerous applications, including transgenesis... Figure 1: Mechanism of the piggyBac™  transposase/transposon gene modification system and the ...genetic manipulation in mammalian cells until 2005 [1]. Like other transposons, piggyBac™ has two components...The predicted frequency of ‘TTAA’ in the genome is 1 in every 256 base-pairs of DNA sequence, making it...technologies and strategies for their projects. References 1. L. E. Woodard and M. H. Wilson, “piggyBac-ing models...technology that may be used for a variety of research applications, including making transgenic cell lines and ...
  17. Tips and Tricks for Using Golden Gate Modular Cloning (MoClo)

    Type
    Blog Post
    Published
    July 8, 2025, 1:15 p.m.
    ... process. Also refer to Figure 1 for a visual overview! Figure 1: General overview of the MoClo...part from an Addgene MoClo kit, to construct a Level 1 vector with a promoter and terminator flanking the...acceptor (bottom) for CDS1 parts. (B) Example Level 1 assembly. The choice between different Level 0 vectors...properly. Do this sequentially for your Level 0, Level 1, and Level 2 assemblies using the plasmid sequence...after each transformation. This could be as few as 1–2 colonies if you’re an experienced MoClo user, but...efficiency. This can be done through domestication, which is the modification of a DNA sequence to remove a ...with every Addgene MoClo kit through their online catalog pages. We guarantee this will save you a lot of...
  18. Antibodies 101: Choosing the Right Isotype

    Type
    Blog Post
    Published
    April 6, 2023, 3 p.m.
    ..., rather than a broadly  reactive secondary (Fig. 1). For example, an anti-mouse IgG2a secondary would...IgG2b > IgG1 (Manning 2012).      Figure 1: Broadly reactive versus subclass-specific antibodies...antibody binding and therefore the signal strength (Fig. 1). Monoclonal primaries If you do decide on a monoclonal...raised in a different species.      Table 1: Isotype considerations when choosing antibodies ...Elsevier. https://doi.org/10.1016/s0091-679x(08)60255-1  Manning, C. F., Bundros, A. M., & Trimmer, J. S. ...your experiment (all well validated for your application, of course!) When the stars are aligned and the...factors that affect isotype choice. Target and application should be considered The first question you may...
  19. Exploring Applications of the Bioluminescent HiBiT Tag

    Type
    Blog Post
    Published
    Oct. 2, 2025, 1:15 p.m.
    ...reconstitutes a fully functional luciferase enzyme (Figure 1). Addition of substrate generates a proportionate ...questions before creating knock-ins.  Figure 1: Schematic of HiBiT tagging technology.   The...overcomes these challenges and enables precise quantification with with nothing more than substrate addition...real time. Let's take a closer look at several applications of this technology. In each section below, we...LgBiT fusion proteins to track how specific modifications to the binding sites and various isoforms led...
  20. Which Fluorescence Microscopy Technique is Best for Me?

    Type
    Blog Post
    Published
    Oct. 10, 2017, 1:57 p.m.
    ... microscopy contrast technique in modern biology (1). When performed correctly, fluorescence microscopy...relatively thicker three dimensional sample (see Figure 1); similar to an MRI or CT scanner. This is accomplished... the resolution of a light microscope (see Figure 1). What microscopy technique should I use for my experiment...new sample I always start by asking two questions: 1) Is the sample dynamic or static? 2) Is the sample...modern day fluorescence microscopes (see Table 1). Thin dynamic samples Ex: monolayers of live cells with...excitation light can push imaging depths closer to 1 mm. Traditionally, 2-photon has been a very slow imaging...manufacturers have similar information References 1. Lichtman JW, Conchello JA. Fluorescence microscopy...
Showing: 81 - 100 of 621 results