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Showing: 361 - 390 of 841 results
  1. Illuminating Epigenetics with A FRET Based Biosensor

    Type
    Blog Post
    Published
    Nov. 19, 2015, 3:30 p.m.
    ...genes should be ‘read’ by the cellular machinery. This is how most cells in the body contain the same ...complex of DNA and histone proteins that compacts cellular DNA into chromosomes and reduces the risk of dangerous...histones changes, then gene expression can change as well. The more frequently and tightly bound DNA is to...the more compacted it becomes. This prevents the cellular machinery from physically interacting with the...function. Angelman syndrome is characterized by intellectual and developmental disability, jerky movements...visualise changes in histone methylation in living cells. Essentially this reporter construct consists of...recognise lysine 27 methylation. When tested in living cells where methylation of these sites was controlled,...
  2. Plasmids 101: Using Transposons in the Lab

    Type
    Blog Post
    Published
    July 6, 2021, 1:28 p.m.
    ...vitro as well as in vivo in yeast, plant, insect, and mammalian cells, including human cells. piggyBac...is active in vertebrates and integrates in human cells at rates similar to retroviral vectors. The hyperactive...piggyBac has an integration efficiency in human cells similar to retroviral vectors. The hyperactive PB...transposase (hyPB) is ~10-fold more active in mammalian cells compared to the codon-optimized wild-type piggyBac...G/C)TNA. Tol2 can deliver 10-11 kB to mammalian cells without decreased efficiency, with a maximum cargo...and has lower efficiency of integration in human cells than piggyBac and Sleeping Beauty. Minimal Tol2 ... or barcodes. When transposons are delivered to cells or a model organism, they insert into the host’s...
  3. Of Myc and Men

    Type
    Blog Post
    Published
    Jan. 19, 2023, 2:15 p.m.
    ...For about as long as the disciplines have existed, cell and molecular biologists have been continuously ... peer into the mysterious, microscopic world of cells. The development of antibodies as tools allowed ...was the existence of high quality antibodies for well defined peptides. Munro and Pelham’s first published...monoclonals would help the field explore Myc’s role in cell proliferation and tumorigenesis.  Using two different...the same antibody developed almost 40 years ago? Well…kinda. In some cases, antibody providers are distributing... human IgG2, mouse IgE, goat IgG, (and more!) as well as the original mouse IgG1. And the refinement of...specific for human c-myc proto-oncogene product. Mol Cell Biol 5:3610–3616. https://doi.org/10.1128/mcb.5.12.3610...
  4. Troubleshooting and Optimizing a Western Blot

    Type
    Blog Post
    Published
    Sept. 17, 2024, 1:15 p.m.
    ...check its subcellular location and solubility. If it’s membrane-bound or located in a subcellular compartment...reagent. Be aware that this approach requires excellent attention to detail, since you’ll end up with ...question before running one.  Good on gradients? Excellent! Now, let’s head west, intrepid reader! Protein...strengths. If that’s not working, consider using a subcellular fractionation kit or a lysing protocol developed...samples and reference ladders are not next to empty wells. Most people will simply load an extra ladder or...replicate (ie, leftover sample) to fill the relevant wells. Similarly, if you load a gel and then forget to...the time with smaller tasks, or simply enjoy some well-deserved down time while waiting for your timer ...
  5. Your Top Requested Plasmid in 2016!

    Type
    Blog Post
    Published
    Jan. 11, 2017, 8:47 p.m.
    ...both SpCas9 and your gRNA in a variety of mammalian cell types. Purpose  SpCas9 This plasmid expresses Streptococcus...the Zhang lab has tested in a variety of mammalian cell lines. Cas9, of course, is the key component of ... puromycin resistance gene enables selection of cells with the plasmid post transfection. The 2A "self...can be used to transfect a variety of mammalian cells and can be modified for viral trasduction (see the...resistance gene that made it less effective in certain cell lines. This point mutation has been corrected in... your gRNA of interest in a variety of mammalian cell lines. Alternative forms of this vector contain ...directed repair. You can find all of these variants, as well as links to the Zhang Lab's Nature Protocols Publication...
  6. Negative Can Be Positive: Open AAV Data with Addgene

    Type
    Blog Post
    Published
    Sept. 6, 2022, 1:15 p.m.
    ...scientists. What works well in one cell or neuron type may not work well for a neighboring cell type, even within...options while AAV8 (82%) and AAV9 (84%) were both excellent at infecting our target neurons (Figure 1). However... conditions (3,5,8), injection titers (1,2), and cell types used for packaging viral particles (6), can...methods and image descriptions, a minimum n = 2, and well labeled high- and low-magnification images demonstrating... vector performance in various brain regions and cell types. Power in numbers A Pubmed search for “AAV....169 Gruntman, A. M., Su, L., Su, Q., Gao, G., Mueller, C., & Flotte, T. R. (2015). Stability and compatibility...
  7. The PAM Requirement and Expanding CRISPR Beyond SpCas9

    Type
    Blog Post
    Published
    Aug. 20, 2020, 2:30 p.m.
    ...Class 2 CRISPR-Cas System. Cell 163:759–771 . https://doi.org/10.1016/j.cell.2015.09.038 Find plasmids...are capable of cleaving genomic DNA in mammalian cells and zebrafish embryos, and they can be used to modify...domains and allows for expanded PAM recognition as well as increased specificity and lower off-target activity... adapted for targeted RNA cleavage in mammalian cells. The REPAIR (RNA Editing for Programmable A to I...Han S, Joung J, Belanto JJ, Verdine V, Cox DBT, Kellner MJ, Regev A, Lander ES, Voytas DF, Ting AY, Zhang... DBT, Gootenberg JS, Abudayyeh OO, Franklin B, Kellner MJ, Joung J, Zhang F (2017) RNA editing with CRISPR-Cas13...reveals specificities of Cpf1 endonucleases in human cells. Nat Biotechnol 34:863–868 . https://doi.org/10.1038...
  8. 5 Reasons to Use Reddit for Science Communication

    Type
    Blog Post
    Published
    Oct. 20, 2016, 2:30 p.m.
    ...blog The blog has many other excellent posts on science career topics as well. Instead of rewriting or coming...everyone, particularly if you’re more interested in selling a product than communicating your ideas with people...has great questions! 2. The r/Science subreddit is well moderated. One of our original worries about sharing...rousing the trolls. 3. The AMA process was simple and well organized. You can check out the r/Science AMA Submission...with our general mission to share- as opposed to sell- science. 4. You can prepare answers beforehand....answers off the cuff, but like to be able to provide well thought out responses. I hung out with Joanne as...small quibble. If you are not too worried about selling yourself and really do just want to get information...
  9. Plasmids 101: What is a plasmid?

    Type
    Blog Post
    Published
    April 2, 2020, 6:17 p.m.
    ... small circular piece of DNA found in bacterial cells, and someone new to plasmids may need some extra...and designed to introduce foreign DNA into another cell. Minimally, lab-created plasmids have an origin ...the ability of plasmids to self-replicate within a cell make them attractive tools for the life scientist...component for expression vectors: determines which cell types the gene is expressed in and amount of recombinant...plasmids also have selectable markers for use in other cell types. Primer Binding Site A short single-stranded...newly inserted gene is transformed into bacterial cells and selectively grown on antibiotic plates.  Importantly...plasmids to manipulate gene expression in target cells. Characteristics such as flexibility, versatility...
  10. Management for Scientists: Giving Feedback

    Type
    Blog Post
    Published
    Feb. 6, 2015, 2:46 p.m.
    ...aspect of being a successful manager. Great bosses tell people where they stand clearly and routinely. They... are clear with each employee about what they do well and where they need to improve, and they’re also...making it a concrete goal to say “thank you, job well done” to one of your employees every day. Prepare... is usually good. Don’t pretend something went well when it didn’t… but don’t “punish” someone for a...say worked out best? What 3 things worked least well? Manager provides feedback (may be the same as ...best.  Here are the 3 things that worked least well. Find out the Effect of the Feedback: How does...this feedback compare with your own perception? Tell me your interpretation of my feedback to you. What...
  11. March for Science

    Type
    Blog Post
    Published
    April 21, 2017, 2:30 p.m.
    ... details for the march in Washington as well as the satellite marches. Anyone can join the marches or ... by Addgene or its staff. In Washington, D.C. as well as sister locations on April 22, 2017, scientists...government protects (and often funds [3]) scientists as well as other citizens. Thus civilization proceeds in...lists over 200 partner organizations, and 514 satellite marches are scheduled to take place around the... a success. Below are resources for the march as well as other science advocacy opportunities. Information...conversation about science’s role in government as well as active advocacy will be required. Information...Website The Washington Post: Trump administration tells EPA to freeze all grants, contracts The Guardian...
  12. Harnessing Bacterial Toxins for Allelic Exchange

    Type
    Blog Post
    Published
    Aug. 15, 2019, 12:30 p.m.
    ... that converts sucrose into a toxic metabolite. Cells that have undergone a double crossover will not ...contain sacB, allowing them to grow on sucrose. Cells that have only gone through the single cross over...counter-selection escape). The rhamnose induction system is well-characterized and quite tight (Giacalone et al.,...., 2006). The Chen lab demonstrated excellent counter-selection which enabled very efficient recombineering...desired deletion directly into cut vector with excellent efficiency using a commercial isothermal assembly...Enterobacteriaceae including in E. coli O157:H7, Shigella flexneri, Enterobacter cloacae, and Serratia marcescens...marcescens and have created dozens of deletions as well as insertions with this system (Lazarus et al., ...
  13. Tetbow: Bright Multicolor Labeling for Neuronal Tracing

    Type
    Blog Post
    Published
    Jan. 24, 2019, 2:24 p.m.
    ...imaging with single-cell resolution using chemical cocktails and computational analysis." Cell 157.3 (2014):... of the XFP genes is introduced at ~2 copies per cell per color, following a Poisson distribution. To ... optimal expression of XFPs. Any longer and the cells may start to show morphological abnormalities due...XFP genes have to be introduced at ~2 copies per cell per color to achieve the highest color variations... wait too long, as too much XFP is toxic to the cells. Inadequate expression levels of XFPs - Reduce the...video below depicting dendrite wiring of mitral cells.   Many thanks to our guest bloggers Richi Sakaguchi...circuitry with an index-optimized clearing agent." Cell reports14.11 (2016): 2718-2732. PubMed PMID: 26972009...
  14. Meet the New Addgene Board Members!

    Type
    Blog Post
    Published
    April 28, 2020, 1:14 p.m.
    ...read some of the seminal papers on cell cycle discovery from Lee Hartwell and Paul Nurse,” Stegmeier says...regulate cell division. And that really got me hooked on genetics.” As a postdoc in Stephen Elledge at Harvard...a great chemistry teacher in 10th grade and then fell in love with science,” she says. In 11th grade she...high-resolution tracking of more than 1 million cancer cells under drug treatment.” Stegmeier especially finds...Belgium. “That’s where I not only got incredibly compelled by wet bench molecular research, but also became...these inefficiencies is pretty remarkable. I was compelled to be part of that.” He’s deposited AAV constructs...
  15. Hot Plasmids: FRET-Based Biosensors

    Type
    Blog Post
    Published
    May 6, 2014, 1:07 p.m.
    ... there is one problem: how to get that into the cells of interest,” Griesbeck said. Because they are chemical...understand the connection between molecular- and cellular-level events and behavior. It’s a problem that...advantage for observing events taking place inside cells that are on the move, such as T lymphocytes. Griesbeck...-binding protein, troponin C (TnC), from muscle cells. They identified a toadfish TnC variant which had...cAMP-responsive element-binding protein (CREB) in living cells. “Now we are making this really good,” Griesbeck...FRET-based sensor proteins, particularly for the intracellular imaging of transition metal ions, such as zinc...also present challenges in that they are found in cells at much lower concentrations than calcium, requiring...
  16. Plasmids 101: NGS Quality Control for Pooled Libraries

    Type
    Blog Post
    Published
    Oct. 26, 2017, 1:59 p.m.
    ...recently re-amplified our distribution stock of the Brunello Human gRNA library, and we thought it would be... Typically, Addgene uses electrocompetent Stbl4 cells when performing amplifications, and we use electroporation...DNA. This bias can be counteracted by growing the cells on solid plates, where each transformant forms its...own colony, uninfluenced by the growth of other cells. For libraries where the plasmids are all very similar...The colonies are then scraped off the plates and pelleted for DNA extraction. Prepare library product for...PCR. A diagram of the product we created for the Brunello library is shown in Figure 2. You can use a small...plotted as a histogram, the counts will give you a bell curve of the abundance of each component of your...
  17. Plasmids 101: Dimers and Multimers

    Type
    Blog Post
    Published
    Jan. 10, 2023, 2:15 p.m.
    ...at lower copy numbers within bacterial cells, and bacterial cells with multimers grow more slowly compared...remain intact, plasmid multimers function just as well as monomers. However, due to their larger size, ...stable and more prone to being lost in bacterial cells compared to monomers, although this can be prevented...increase the frequency of base substitution in human cells. J Biol Chem. 2011 Mar 25;286(12):10017-26. doi:...plasmids leading to the formation of plasmid multimers. Cell. 1976 Dec;9(4 PT 2):707-16. doi: 10.1016/0092-8674...supercoiled plasmid DNA concatemers in mammalian cells. J Gene Med. 2009 May;11(5):444-53. doi: 10.1002...essential for plasmid monomerization and stability. Cell. 1984 Apr;36(4):1097-103. doi: 10.1016/0092-8674...
  18. Expanding the Targeting Scope and Editing Efficiency of Adenine Base Editors

    Type
    Blog Post
    Published
    March 17, 2020, 1:32 p.m.
    ...gives a talk at the Cell Symposia: Gene- and Cell-based Therapies: CRISPR, Stem Cells, and Beyond meeting...contains the deoxyadenosine deaminase, TadA-7.10 (Gaudelli et al., 2017). The idea was to evolve a TadA-7.10...III product is produced and can infect bacterial cells. If a phage does not deliver an active variant, ...passage from the infected to a fresh uninfected host cell culture). This dilution step represents the major...but gets manually passaged from an infected host-cell culture to an uninfected culture which results in...efficiently and in more contexts. References Gaudelli NM, Komor AC, Rees HA, Packer MS, Badran AH, Bryson...
  19. Building and Validating Recombinant Antibodies: A Case Study

    Type
    Blog Post
    Published
    April 5, 2022, 1:20 p.m.
    ...cryopreserved hybridomas, immortalized cells created by fusing an activated B cell that produces the antibody of...of interest with a myeloma cell. This RNA was then used to generate cDNA, which  was used as a template...of hybridoma generated mAbs is that if the frozen cell line becomes non-recoverable, the stock of the mAb...hybridoma stocks, without having to grow up the cells. This RNA could then be used to generate functional...immunofluorescence-immunocytochemistry (IF-ICC.) This method was chosen because cells transfected with a plasmid to express the target... could be screened in a high-throughput manner. Cells were labeled with both a hybridoma generated mAb...hybridoma mAb.  While screening by IF-ICC worked well for identification of the correct clones, it was...
  20. CRISPR 101: Non-Homologous End Joining

    Type
    Blog Post
    Published
    April 16, 2015, 3:45 p.m.
    ...Translocations in Human Cells Are Generated by Canonical Nonhomologous End-Joining. Molecular Cell 55:829–842 . ...Genome Editing Specificity. Cell 154:1380–1389 . https://doi.org/10.1016/j.cell.2013.08.021 Waters CA, Strande... chromosomal DSBs. It is important to know that cells possess two major repair pathways – Non-Homologous... steps Unlike HDR, NHEJ is active throughout the cell cycle and has a higher capacity for repair, as there...should take less than an hour, thus a population of cells constitutively expressing a targeted Cas9 should...CRISPR Protocol for Genomic Deletions in Mammalian Cell Lines [Video] Pooled CRISPR Libraries Offer Genome-Wide...
  21. Antibodies 101: Conjugation

    Type
    Blog Post
    Published
    March 26, 2024, 1:15 p.m.
    ...and Protein Modifications in Cells and Tissues in Situ. Curr Protoc Cell Biol 89:e115. https://doi.org...need a little help to be useful. Mainly because, well, antibodies are kind of hard to see. To solve this...imaging instruments or X-ray film and lends itself well to assays like western blots and ELISAs. Chromogenic... like proximity ligation, immuno-PCR, and single-cell applications (Hegazy, et al., 2020; Niemeyer, et...throughout antibody sequences, up to 80 per antibody (Mueller, et al., 1988). If some of those lysines are in...doi.org/10.1002/cpcb.115  Mueller BM, WrasidloO WA, Reisfeld RA (1988) Determination of the Number of e-Amino...epitope and transcriptome measurement in single cells. Nat Methods 14:865–868. https://doi.org/10.1038...
  22. Visualizing Protein Turnover In Situ

    Type
    Blog Post
    Published
    Jan. 16, 2018, 3:20 p.m.
    ...proteins in cells. Homeostatic regulation of protein abundance is essential for normal cell function, and...one particular protein in neurons or in any other cell type. However, we cannot distinguish new from old...facilitate the visualization of specific proteins in cells. Tagged protein can easily be overexpressed from...techniques to follow translation in living single cells. However, before CRISPR-Cas9 these techniques were...interests, suspected to interact, are added to a cellular sample. Both antibodies have a short antibody ... turnover of specific endogenous proteins in any cell type. Exciting! Many thanks to our guest blogger... how small molecule fluorophores can be used for cell labeling Check out other protein tagging strategies...
  23. Announcing the Winners of the 2021 Michael Davidson and Roger Tsien Commemorative Conference Awards

    Type
    Blog Post
    Published
    Aug. 5, 2021, 12:15 p.m.
    ...sensitive GFP2 (roGFP2)-based biosensors for live cells. His work focuses on the enzyme hydropersulfide-... understand the processes that happen inside the cell,” says Pedre Pérez. Figure 2: Micrographs...Micrographs of the biosensor expressed in the human cell line, Hep3B. From left to right: Mitotracker Red, GFP...studies opioid use disorder. Her goal is to identify cell populations in the brain that contribute to the ...will explore the connectivity patterns of these cells and the functional contribution to a variety of ...administration and withdrawal to explore how these cells may encode the negative affect associated with drug...library of mutant sensors expressed in a mammalian cell line engineered to be electrically excitable. The...
  24. Giving gRNAs a Facelift - Synthetic and Beyond

    Type
    Blog Post
    Published
    Oct. 20, 2022, 1:15 p.m.
    ...gRNA technology have enhanced targeting efficacy as well as the unnecessary stress of worrying about the ...evolved ways to prevent degradation of important cellular RNA molecules with post translational modifications...deoxynucleotides. A partially DNA gRNA is surprisingly well-tolerated by the Cas9 protein and can increase on-target...slightly more efficient and less toxic to mammalian cells (Allen, et al., Frontiers in Genome Editing).  Some...transfection efficiency and even track localization in cellular experiments. There are many suitable dyes to choose...enhance CRISPR-Cas genome editing in human primary cells. Nat Biotechnol 33, 985–989 (2015). https://doi....Enhance CRISPR Genome Editing Systems in Mammalian Cells. Frontiers in Genome Editing, 28 (2021). https:/...
  25. Design Tips for Prime Editing

    Type
    Blog Post
    Published
    Jan. 23, 2025, 2:15 p.m.
    ...editing systems by manipulating cellular determinants of editing outcomes. Cell, 184(22), 5635-5652.e29. https...Guide RNA and Target DNA. Cell, 156(5), 935–949. https://doi.org/10.1016/j.cell.2014.02.001 Yan, J., Oyler-Castrillo...type of edit, genomic context, delivery strategy, cell type, and goal of the experiment. Now, onto the ...nicking of the unedited strand and encourage the cell to use the edited strand as a template during DNA...also allows certain unintended edits to escape cellular surveillance. To limit unintended incorporation...https://doi.org/10.1016/j.cell.2021.09.018 Nelson, J. W., Randolph, P. B., Shen, S. P., Everette, K. A...
  26. Pathways Over Time Plasmids Engage Students in Functional Genomics Research

    Type
    Blog Post
    Published
    May 22, 2018, 1:38 p.m.
    ...is non-pathogenic, well-studied and inexpensive. In addition, a complete set of well-annotated deletion...contain methionine. (This allows cells carrying nonfunctional as well as functional MET genes to grow.... or students clone similar sequences from a less-well studied organism into overexpression plasmids. Students...synthesis in S. cerevisiae (Figure 1) occurs through a well-characterized pathway with multiple enzymatic steps... is available at our Investigations in Molecular Cell Biology Website. Many thanks to our guest blogger...right) has taught courses in biochemistry, molecular cell biology and genetics at Boston College. She is particularly...
  27. A Look Back at One Year of Plasmid Sharing for COVID-19 Research

    Type
    Blog Post
    Published
    July 12, 2021, 1:15 p.m.
    ...depends on its spike protein to bind ACE2, the host cellular receptor. To more easily study the spike variants...protein, called HexoPro, was developed by Jason McLellan’s lab. This version of the spike protein was developed... investigate how the virus interacts with human cells. Addgene’s mammalian target plasmids express these...scientists used the genome-wide CRISPR libraries, Brunello (knock out) and Calabrese (activation), from Addgene...for SARS-CoV-2 entry into human lung epithelial cells (Biering et al., 2021). In their search, they found...packaging) and contain an IRES-Puro marker for stable cell clone selection. For more information on these plasmids...Lavinder JJ, Ippolito GC, Maynard JA, Finkelstein IJ, McLellan JS (2020) Structure-based design of prefusion-...
  28. 6 Tips for Grant Writing

    Type
    Blog Post
    Published
    Oct. 18, 2016, 2:30 p.m.
    ...to give yourself plenty of time when writing a fellowship proposal. Yes, yes, I hear you saying “We know...research (either because of expertise, equipment, or excellence of the institution). Likewise, if you’re staying.... Become a science communicator More and more fellowship applications are asking for a 200-300 word explanation...explanation of your research for non-scientists. Most fellowships are funded by the general public (either through...may make your perfectly reasonable paragraph unintelligible to a lay audience. My lay paragraph typically...assisting me with applications for much larger fellowships. Also, if you were awarded money to carry out...Cambridge University where he studied mechanisms of cell division. Recently Seán got the entrepreneurial ...
  29. The Materials Science of Optogenetics Experiments

    Type
    Blog Post
    Published
    Sept. 17, 2015, 2:30 p.m.
    ...currently a Postdoctoral Fellow in the lab of Mary Jeanne Kreek at the Rockefeller University.  His interests...protein-coupled vertebrate rhodopsin in cerebellar Purkinje cells. The Journal of biological chemistry. ...Pharmacology and Optogenetics. Cell 162.3 (2015): 662-674. doi: 10.1016/j.cell.2015.06.058. Pubmed PMID: 26189679...Derek Simon! Derek P. Simon received his PhD in Cellular and Molecular Biology from the University of Michigan...PMCID: PMC3466483. 4. Kim TI, et al. Injectable, cellular-scale optoelectronics with applications for wireless...
  30. Truncated gRNAs for Regulating Gene Expression

    Type
    Blog Post
    Published
    Jan. 10, 2017, 3:37 p.m.
    ... genetic loci within a single cell. One might imagine transfecting cells with both the nuclease-positive...Perhaps most importantly, most Cas9 orthologs are less well characterized than the conventionally used SpCas9... both to lower relative nuclease efficiencies as well as to more stringent targeting rules that result...nuclease-competent Cas9, obviating the need to generate new cell lines or transgenic animals expressing dCas9 as ...reliance on orthogonal Cas9 species. Within a single cell, full-length guides targeting one set of genetic...nanoparticles as drug delivery systems. She is also a NASA Fellow studying biosignature preservation in Mars analogue...knockin mice for genome editing and cancer modeling." Cell 159.2 (2014): 440-455. PubMed PMID: 25263330. PubMed...
Showing: 361 - 390 of 841 results