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Showing: 521 - 560 of 858 results
  1. Antibodies 101: Selecting the Right Antibody

    Type
    Blog Post
    Published
    March 15, 2022, 1:15 p.m.
    ...exciting new project aimed at understanding how a critical cellular pathway is regulated. You’ve read all...do you know about the vendor and the vendor’s technical support? An antibody from a vendor that you use...frequently, with a responsive and knowledgeable technical support team, is a safer bet than one from a large... all validation is equal and you should think critically about what data is and is not shown on an antibody...
  2. Viral Vectors 101: An Introduction to AAV

    Type
    Blog Post
    Published
    May 30, 2023, 1:15 p.m.
    ...and can be specifically targeted to a number of different cell types even when systemically administered...with maximum “trunk” space for genetic cargo. Typically, when researchers speak about AAVs, they are actually...ITRs and serotypes The names of AAVs contain two numerical designations, separated by a slash, that indicate...
  3. To Each HIS Own

    Type
    Blog Post
    Published
    March 2, 2023, 2:15 p.m.
    ...Much of today's biological research requires a close examination of specific proteins within a system...without eluting the target protein and needs to be empirically determined. In addition, some metal ion substrates...function. B, The string of histidines in the tag is typically between 6 to 9 residues long. The small size of...Enfors SO, Persson I, Nilsson B and Uhlen M. Large-scale affinity purification of human insulin-like growth...
  4. Plasmids 101: The protein expression toolbox

    Type
    Blog Post
    Published
    Feb. 16, 2023, 7:05 p.m.
    ...protein expression in mammalian cells: easy to use biological tools are abundant! In this post, we will review...that! CRISPR interference (CRISPRi) targets a catalytically dead Cas9 fused to a transcriptional repressor... protein, then these systems need to be site-specifically knocked in. This can be labor intensive and ...and target-specific protein degradation. Nature Chemical Biology. May 2018. 14(5): 431-441. PubMed PMID...
  5. RNA Extraction Without A Kit

    Type
    Blog Post
    Published
    March 24, 2020, 1:15 p.m.
    ...widely known of these products is TRIzol® (also called TRI Reagent®, RNAzol®, QIAzol®  and sold by many... within cells or tissues- they don’t actually chemically stabilize the RNA molecules (Allewell and Sarma... MacDonald RJ, Rutter WJ (1979) Isolation of biologically active ribonucleic acid from sources enriched...Guanidinium Thiocyanate–Phenol–Chloroform Extraction. Analytical Biochemistry 162:156–159. https://doi.org/10.1016...
  6. Enhancing CRISPR Targeting Specificity with eSpCas9, SpCas9-HF1, & HypaCas9

    Type
    Blog Post
    Published
    Dec. 16, 2015, 3:30 p.m.
    ... Not only is CRISPR having effects on various biological disciplines, the base technology itself is constantly...at non-target sites. Means to decrease these so-called “off-target effects” have included using a Cas9... the Broad Institute, the Joung lab at Harvard Medical School, and the Doudna Lab at Berkeley set out ...afforded by gRNA binding at non-target sites would theoretically decrease off-target cutting. Figure 1...
  7. Hot Plasmids and Viral Preps - January 2021

    Type
    Blog Post
    Published
    Jan. 5, 2021, 2:15 p.m.
    ... Jesse Zalatan’s lab deposited plasmids for a chemically inducible CRISPRa system in yeast is mediated...Find the yeast CRISPRa plasmids here Reduce the scale of your CRISPR screens by using this lentiviral ...paired guides per construct and allows a reduced scale in screens without any reduction in performance ... channelrhodopsin (C1V1) targeting parvalbumin cortical interneurons is now available as a ready to use...
  8. Corralling and Cornering the Goldilocks Antibody

    Type
    Blog Post
    Published
    Aug. 9, 2022, 1:15 p.m.
    ...researchers to identify and isolate very specific biological targets. However, as popular and useful antibodies...antibodies, creating a potentially unlimited supply of identical antibodies (See Fig 1.). rAbs are a relatively...has specific binding and has a strong signal. We call the unique pattern of the antibody binding “distinct...TS (2015) The Economics of Reproducibility in Preclinical Research. PLoS Biol 13(6): e1002165. https://...
  9. Antibodies 101: Choosing the Right Isotype

    Type
    Blog Post
    Published
    April 6, 2023, 3 p.m.
    ...choosing antibodies   Complexity is a key factor Biological systems tend to be complex with a variety of ...multiple targets in parallel. In these cases, it is critical that users choose antibodies that are easily distinguishable...staining multiple targets indirectly, you must strategically plan primary/secondary antibody pairing such...Fisher, S. K. (1993). Chapter 15 Postembedding Immunocytochemical Techniques for Light and Electron Microscopy...
  10. A Look at Addgene's QC Process

    Type
    Blog Post
    Published
    May 6, 2025, 1:15 p.m.
    ...plasmids. These are prone to error — both human and biological. Even the most high-fidelity polymerases can ...the correct inserts, tags, promoters, and other critical functional components. Fun fact! Some older plasmids...sequences. These sequences can also be confirmed or theoretical. No matter the level of information that is provided...the raw NGS reads and reassemble using a program called Geneious. Here, the raw reads are mapped against...
  11. Story of a SynBio Startup: RevBio's Epiphany (or Lack Thereof)

    Type
    Blog Post
    Published
    June 5, 2014, 3:32 p.m.
    ...things more interesting, we are working in a new technical discipline that nobody understands (synthetic ...thing is opening a pizza joint. Silly ideas (mining local salt deposits to sell at farmers markets), and serious...that survived the literature review, survived technical feasibility analysis, and was a marketable product...and rapidly indicate their presence. They are genetically modified organisms, and GMOs have a bad reputation...
  12. Academic vs. Industry Postdocs

    Type
    Blog Post
    Published
    Nov. 13, 2018, 1:22 p.m.
    ...can be long—5 years or more, especially in the biological sciences—whereas industry postdocs have a set...course, you might have less time to explore scientifically since you can’t afford to spend too much time...Unless your academic lab is closely involved with clinical trials or has ties to industry, the drug discovery...industry postdoc, you might find yourself feeling scientifically isolated if no other postdocs are in your department...
  13. Tips for a 1st time AAV user (by a Rookie AAV user)

    Type
    Blog Post
    Published
    Oct. 23, 2018, 11:49 a.m.
    ...margins of my protocol. While these tips weren’t critical to the experiment, they definitely made my life...qPCR Protocol for more details. Pro Tips When calculating the titer for your AAV, remember to account for...control (NTC) should always be included. While the physical titer generated by qPCR is useful, I test a few...tool for gene expression in mammals Use the PEI calculator for planning AAV packaging transfections Find...
  14. The Scientific Conference Poster Session: Tips for Success

    Type
    Blog Post
    Published
    Aug. 29, 2019, 12:50 p.m.
    ...therapeutic strategies to target it, than you typically would at a microbiology meeting. Create an outline...lab mates, and PI can provide feedback on your technical presentation, but those outside of your field ... through the list at the session so you can strategically use your time. Don’t have access to a list of...titles to find the ones you’d like to revisit. Strategically traverse the sea of posters If you come prepared...
  15. PRIDICT: Predicting Efficiencies of Prime Editing Guide RNAs

    Type
    Blog Post
    Published
    June 25, 2024, 1:15 p.m.
    ... Liu, 2023). This method uses a prime editor (typically a Cas9 H840A nickase fused to a reverse transcriptase... design of the pegRNA has been shown to play a critical role in the editing efficiency of prime editing...experimentalist, and especially shines once large-scale prime editing experiments come into play. Nicolas...s41587-023-01678-y Li, X., Chen, W., Martin, B. K., Calderon, D., Lee, C., Choi, J., Chardon, F. M., McDiarmid...
  16. Hot Plasmids: Summer 2025

    Type
    Blog Post
    Published
    Aug. 28, 2025, 1:15 p.m.
    ...the ωRNA (TnpB) or a gRNA (Cas9). Drawings not to scale. Created with BioRender.com. Steven Jacobsen...Rodriguez-Fraticelli recently developed an approach called Simultaneous Tracking of Recombinase Activation...recombinase payload activates a floxed reporter gene (genetically encoded or delivered separately). Figure...Cre-dependently to allow tracing exclusively from genetically determined cells. This version of ATLAS works...
  17. Plasmids 101: Knockout/Knock-In Plasmids

    Type
    Blog Post
    Published
    Dec. 1, 2016, 3:30 p.m.
    ...your gene of interest is difficult to target specifically with a gRNA). Be sure to keep these techniques...sequences are exchanged between two similar or identical molecules of DNA. Gene targeting takes advantage...homology is required, but 6 to 14 kb of homology is typical for targeting constructs. In the example shown ...cells participating in development or other physiopathological events to which the chosen promoter responds...
  18. Tips for Using BLAST to Verify Plasmids

    Type
    Blog Post
    Published
    May 29, 2014, 1:29 p.m.
    ... 2017. At Addgene, we continually use the Basic Local Alignment Search Tool (BLAST) provided by NCBI. ...BLAST sequence databases from the dropdown menu. Typically, we use the default nucleotide database “Nucleotide...” program for blastn so that you can extract practically every single reliable base pair from your results... the “Align two or more sequences” option to drastically reduce waiting time for search results. Optimizing...
  19. Minigenomes - a Safe Way to Study Dangerous Viruses Like the Ebola Virus

    Type
    Blog Post
    Published
    March 17, 2016, 2:30 p.m.
    ...-length viral genome (Figure 2). While it is technically possible to encode all four viral genes in the... (see Uses of Minigenome System). From a more technical standpoint, a plasmid with all four genes and ... gene by altering the amount transfected (see Technical Tips). Minigenome replication and transcription...compounds which often target the viral polymerase. Technical tips It is important that all of these plasmids...
  20. Tips for Screening with Yeast Two Hybrid Systems

    Type
    Blog Post
    Published
    Oct. 22, 2015, 2:30 p.m.
    ...lab tool. In the classic two hybrid system (also called the interaction trap), genes encoding proteins ...experiments. False positives can occur even in small scale experiments, although these can often be accounted...that the configuration of your fusion proteins physically blocks the binding sites for the protein partner...Tachihara, K., Umezawa, Y.l. Split luciferase as an optical probe for detecting protein-protein interactions...
  21. Tips from the Repository Trenches: Using Barcodes to Track Samples

    Type
    Blog Post
    Published
    Oct. 6, 2015, 2:30 p.m.
    ...that, they also help us keep track of the tubes’ physical location in the lab. These barcodes additionally...  freezers depending on the sample type. It is critical for us to know which plate, rack, and freezer ...performs an average of 140 transformations. The lab typically transforms newly deposited samples from Monday...Excel sheet.3. Be specific  - When assigning a physical location to your samples, include as much detail...
  22. Interview: Hodaka Fujii on enChIP, New CRISPR Tools, and More

    Type
    Blog Post
    Published
    Dec. 2, 2014, 7:23 p.m.
    ...been working on development of technologies for biochemical analysis of genome functions such as transcription...researchers to use enChIP in a wide variety of biological systems. We are currently developing several ...Therefore, my lab is dedicated to development of new biological technologies. The locus-specific ChIP technologies... effort to interact with each other, which is critically important, especially for young researchers. ...
  23. Bacterial Toxin-antitoxin Systems as Molecular Biology Tools

    Type
    Blog Post
    Published
    Nov. 1, 2018, 12:35 p.m.
    ...passed down through generations (Figure 1). These so called “plasmid addiction systems” require dividing cells..., plasmid addiction systems have been used as biological tools for a wide range of applications in molecular...become a powerful tool to address a diverse set of biological inquiries. References Ogura, Teru, and Sota...vaccine strain CVD 103-HgR." FEMS Immunology & Medical Microbiology 57.1 (2009): 69-79. PubMed PMID: 19678844...
  24. Transferable Skills Guide: External Collaborations

    Type
    Blog Post
    Published
    April 19, 2018, 1:25 p.m.
    ...gives Snapgene great exposure to the community of biological scientists who use Addgene everyday. To get this...from other institutions personally on conference calls and make sure to maintain these relationships by...speakers for a meetup or recruit volunteers for your local animal shelter. There are many opportunities so ...Universities themselves can help you do this through practical tools like alumni networks. I find it useful to...
  25. What's Your Organism? Expanding Genomic Tools via the NSF EDGE Program

    Type
    Blog Post
    Published
    May 2, 2019, 12:41 p.m.
    ...studying parenting strategies and make important ecological indicators since species live in water and on... as the only Monarch butterfly food. They have chemical pathways generating interesting drug-like compounds...Lab (@EvoEmbryo) September 24, 2018   Xenopus tropicalis (Gary Gorbsky) This is not a new experimental...plants and are unusual enough to be interesting biologically. They have economic importance as harmful weeds...
  26. CRISPR-mediated Plant Base Editors

    Type
    Blog Post
    Published
    Jan. 3, 2019, 1:35 p.m.
    ... defective gene, Xm, the sequence of which is identical to the correct gene, Xw, except for a single base...precisely changes a single base with an efficiency typically ranging from 25-75%, while the success of precise... in the DNA by cutting only a single strand, dramatically reducing the likelihood of detrimental indel...known 'DNA adenosine deaminases' which would theoretically give rise to an adenine base editor. A massive...
  27. Twenty Years of Sharing: Addgene's Viral Vector Service

    Type
    Blog Post
    Published
    July 30, 2024, 1:15 p.m.
    ... ligands (Figure 2). Biosensors, which include calcium and voltage sensors, are the broadest category ...catalog If you’ve been following our blog, you may recall our first 20th anniversary story on CRISPR, where... vectors available in the repository. GCaMP, a calcium indicator (biosensor, by Addgene’s categorization...Waxmonsky, N. C., Swanson, L. E., & Fan, M. (2016). Practical Considerations for Using Pooled Lentiviral CRISPR...
  28. Antibiotic Resistance: An Old Solution but a New Problem

    Type
    Blog Post
    Published
    Nov. 10, 2016, 3:30 p.m.
    ...possess cell walls. As a result, Mycoplasma are intrinsically resistant to this class of antibiotic. Acquired...When antibiotic resistance testing is requested clinically, this involves growing a standardized amount ...certain antibiotic were chosen for treatment. This is called a Kirby-Bauer disk diffusion test or Kirby-Bauer...-trusted method that is frequently used in the clinical laboratory. What can we do to stop the emergence...
  29. Getting the Most from Your Lentiviral Transduction

    Type
    Blog Post
    Published
    April 7, 2016, 2:30 p.m.
    ...contamination. For those labs that prefer a more economical mode of detection, Uphoff et. al. outline a do...engineered with non-native envelopes, a process called pseudotyping. Lentiviruses pseudotyped with the...virus. To circumvent this problem, transductions typically employ the positively charged polycation, polybrene...lentiviral and retroviral vectors.” Human Gene Therapy Clinical Development 25.3 (2014). 175-85. Pubmed PMID: ...
  30. Plasmids 101: E. coli Strains for Protein Expression

    Type
    Blog Post
    Published
    Feb. 10, 2015, 3:06 p.m.
    ...on DNA, or are enzymatically active. For this reason, recombinant proteins are typically expressed in E...medium. Induction timing is important, as you typically want to make sure your cells have first reached...your expression conditions by setting up a small-scale expression experiment to test variables such as ...
  31. Deep Mutational Scanning with One Pot Saturation Mutagenesis

    Type
    Blog Post
    Published
    Feb. 22, 2017, 3:30 p.m.
    ...control over where mutations are introduced, and scalability (see Supplementary Table 1 of Wrenbeck et al)...stretches of sequence could be used. However, a practical limitation is sequencing depth and cost. You need...Measuring the Activity of Protein Variants on a Large Scale Using Deep Mutational Scanning.” Nature Protocols...scanning: assessing protein function on a massive scale." Trends in Biotechnology 29.9 (2011): 435-42. PubMed...
  32. The Advances Behind The World's First Personalized CRISPR Treatment

    Type
    Blog Post
    Published
    Sept. 16, 2025, 1:15 p.m.
    ...regulators. But the speed is impressive on a larger scale, too. The first paper reporting genome editing by..., 2016). Advancing from this invention to KJ’s clinical application in under a decade is an astounding... safety of KJ’s experimental treatment, it was critical to reduce off-target editing as much as possible...P. (2025). Custom CRISPR-Cas9 PAM variants via scalable engineering and machine learning. Nature, 643(...
  33. Antibodies 101: Introduction to Immunofluorescence

    Type
    Blog Post
    Published
    Nov. 16, 2021, 2:15 p.m.
    ...ICC or a tissue in the case of IHC. IF is used specifically when we visualize the antibodies using fluorescence...counterstaining, mounting sample on slides, and confocal   Figure 2: High-level overview of an ...controls to show that your antibodies are binding specifically. For positive controls, aim to use samples that...in an organism that is underrepresented in the biomedical research community. You may have to take some...
  34. Plasmids 101: Gibson Assembly and Other Long-Homology Based Cloning Methods

    Type
    Blog Post
    Published
    March 1, 2016, 3:30 p.m.
    ... regions of homology at their ends, which are typically created by PCR. Then, the fragments are incubated...competent cells. The success rate of this reaction is typically fairly high, so there is usually no need to screen...the bacterial chromosome (up to 100 kb) were specifically cut out via CRISPR and then assembled into a...amplify the fragments of the chromosome, which was technically challenging. Other homology based technologies...
  35. Easi-CRISPR: Generating Knock-In and Conditional Mouse Models

    Type
    Blog Post
    Published
    April 5, 2018, 12:42 p.m.
    ...simple in C. elegans and bacteria. But CRISPRing typical mouse models, including creating Cre-dependent ...on both sides and the T7 promoter on one end. Typically, Easi-CRISPR works best with insertions of 2 kb...models varies from 8.5-100% of pups born, with typical efficiencies of 30-60%. Quadros et al. attribute...2.5x more animals than i-GONAD and is a more technically difficult process. Overall, the main drawback...
  36. PiggyBac-ing Through the Genome Editing Field

    Type
    Blog Post
    Published
    May 31, 2016, 3:30 p.m.
    ...facilitates the integration of the transposon specifically at ‘TTAA’ sites randomly dispersed in the genome...re-integration from the piggyBac™ donor, which is typically found with the wild-type piggyBac™ transposase..., including making transgenic cell lines and genetically-modified cell lines. Furthermore, the use of ...cell engineering team.     Mathew Goodwin is a Technical Sales Specialist at Transposagen. As a gene editing...
  37. How to Design Your gRNA for CRISPR Genome Editing

    Type
    Blog Post
    Published
    Sept. 24, 2020, 1:15 p.m.
    ...desired location of edit; efficiency decreases dramatically when the cut site is >30nt from the proximal... constraints are even more exquisite for the so-called base editor Cas9, which makes DNA changes in the...nuclease-mediated off-target effects.” Further, large-scale datasets of hundreds of genetic screens using genome-wide... sequences targeting a gene to score in order to call that gene a hit.  This is an exciting time for functional...
  38. A Needle in a Base-Stack: Cas9 Structural Biology

    Type
    Blog Post
    Published
    June 4, 2024, 1:15 p.m.
    ... BioRender.com.   Cas9 has two major lobes, called NUC (for nuclease) and REC (for recognition). The...recognizing the PAM on DNA, the CTD is also sometimes called the PAM-interacting (PI) domain. The guide RNA ...conformational state of the HNH domain also allosterically controls RuvC activity through a hinge region...Visualization, and Informatics at the University of California, San Francisco, with support from National Institutes...
  39. 5 Science Rap Videos & Their Creator: Tom McFadden

    Type
    Blog Post
    Published
    Feb. 9, 2017, 3:30 p.m.
    ...African American woman whose cervical cancer cells became a mainstain of biological study without her or her...fossil rocks and their importance in understanding biological history. 4. Please Don't Kill My Hive Beautifully...
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