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  1. Finding Your Science Policy Path

    Type
    Blog Post
    Published
    Sept. 22, 2020, 1:15 p.m.
    ...AAAS Science and Technology Policy Fellow at the Veterans Health Administration. “But, seriously, what even...Science and Technology Policy Fellow (STPF) at the Veterans Health Administration, I could never get one straight...these changes to policy could shift how society interacts with certain scientific areas. Whether you’re ... or even run for office yourself! Plus, at the federal or state level some professional societies host...taken through your own personal lens.  For me, the Veterans Health Administration was the perfect position...example proposals and consider applying for their accelerator for some hands-on guidance.   Check out my webinar...fellowship is that you are often vetted for your general scientific expertise and then once selected, you...
  2. Tips for a 1st Time CRISPR User (by a 1st Time CRISPR User)

    Type
    Blog Post
    Published
    March 7, 2017, 3:30 p.m.
    ... and use temperature to denature and renature the dsDNA. Upon renaturation, you will generate DNA duplexes...Expression of gRNAs Generating Mouse Models Using CRISPR/Cas9 Resources at Addgene.org Generating Stable Cell...inactivate the gene BRAF (a kinase implicated in several human cancers) in A549 cells (a human lung cancer...express Cas9. In these particular experiments, we generated A549 cells stably expressing Cas9 via transduction...52962-LV, Figure 1). Some cells were then used to generate a monoclonal cell lines by limiting dilution. ...Figure 2: Cas9 expression in monoclonal cell lines generated from A549 cells transduced with lentiCas9-blast...lanes 3, 4) were used as controls. Duplexes were generated from BRAF-edited and GFP-edited amplification ...
  3. Mycoplasma Contamination: Where Does It Come From and How to Prevent It

    Type
    Blog Post
    Published
    Oct. 8, 2020, 1:15 p.m.
    ... difficult to eradicate. You can suppress the growth of mycoplasma but cannot eradicate it completely....nutrient-rich and also the best source for mycoplasma proliferation. Plus, it is added to the media after autoclaving...being contamination free. The aerosols that are generated (while talking or pipetting) during working in...leading causes of contamination. These aerosols generated will enter the culture medium during subculturing... contact with a nutrient source, they start proliferating shortly. Once they are present in the laboratory...are used which trigger cellular mechanisms that generate luminescence. This can then be detected by a luminometer...important to prevent contamination rather than eradicating it later. Don’t be scared when mycoplasma infects...
  4. xCas9: Engineering a CRISPR Variant with PAM Flexibility

    Type
    Blog Post
    Published
    March 28, 2018, 6:52 p.m.
    ...SaCas9 with an NNGRRN PAM by mutagenizing the PAM-interacting domain. However, these alternative PAM sequences...often more complex than NGG, resulting in lower overall genome frequency. Despite the progress we’ve made...evolution Hu et al. used phage-assisted evolution to generate and select for Cas9 mutants with PAM flexibility...catalytically dead SpCas9 (dCas9) fused to the bacterial polymerase subunit ω. This construct is designed to activate...another 72 hours of phage-assisted evolution, generating xCas9 2.0-2.6. This second round of evolution... Cas9 variants with activity on non-NGG PAMs, generating xCas9 3.0-3.13. To test xCas9 3.0-3.13, Hu et...transcription. Sites containing NG, GAA, or GAT PAMs averaged 56-91% transcriptional activation compared to ...
  5. AAV Vector Quality Control: Going the Extra Mile with NGS

    Type
    Blog Post
    Published
    Sept. 12, 2017, 1:44 p.m.
    ... by Single-stranded Virus Next-generation Sequencing. Molecular Therapy - Nucleic Acids 4:e260 . https...our viral service to continue our mission of accelerating scientific research. To make sure that adeno-associated...more rigorous quality control, including next generation sequencing (NGS) of the viral genome to confirm... the virus itself. While these impurities are generally considered innocuous for research-grade vectors...likelihood of recombinase-independent expression. Next-generation sequencing (NGS) is a powerful tool that can ...Vivo Persistence after Vector Delivery. Molecular Therapy 12:744–753 . https://doi.org/10.1016/j.ymthe.2005.06.003...Mueller I, Mitsopoulos A, Fan M (2020) A Novel Next-Generation Sequencing and Analysis Platform to Assess the...
  6. Which Fluorescent Protein Should I Use?

    Type
    Blog Post
    Published
    May 20, 2014, 2:06 p.m.
    ...proteins that interact. Indeed, FRET is often used to determine if two proteins interact. Oligomerization...10hours. Temperature: FPs maturation times and fluorescent intensity can be affected by the temperature. For...filter that will pass blue light to the detector/camera, then BFPs are of no use to you. When using more...Oligomerization: The first generations of FPs were prone to oligomerize. This may affect the biological function...parameters (e.g. excitation light intensity, pH or temperature). Photostability: Fluorescent molecules gets ...parameters (e.g. excitation light intensity, pH, or temperature). pH Stability: This parameter is important if...Helpful Websites & Resources: FP guide at Addgene Interactive Visualization of Fluorescent Protein Properties...
  7. CRISPR Methods for Bacteria: Genome Engineering, CRISPRa, CRISPRi, Base Editing, and More

    Type
    Blog Post
    Published
    Sept. 28, 2020, noon
    ...organisms or organism/gene interactions with the host. This scenario allows for several potential CRISPR applications... functions in S. pneumoniae and can be used to generate multiple mutations simultaneously (Jiang et al... with CRISPR to create a system for scarless, iterative genome engineering (Jiang et al., 2015). pCas ... or a dCas9 fused to the omega subunit of RNA polymerase, the lab   successfully repressed or activated...Noting that the more common spCas9 system has generally low efficiencies or can be proteotoxic when used... orthologs to identify a more efficient, well tolerated, Cas enzyme. They identified the Cas9 orthologue...problem than repression, scientists have deposited several plasmid tools that can be used in this way. As ...
  8. Tips for arabidopsis transformation

    Type
    Blog Post
    Published
    Oct. 25, 2018, 1:23 p.m.
    ... transformation. There are many motivations to generate transgenic Arabidopsis, from studying transcriptional... floral drip or dip transformation method. The general steps for this method include: Cloning and transforming...appropriate expression vector is the first step in generating transgenic Arabidopsis. There are a bunch of ...vectors and can be used for promoter swapping and generating N and C terminally tagged fusion proteins with...plants you are transforming into will be your T0 generation. These plants will be ready to transform when...will also increase the number of inflorescences overall, which may improve transformation efficiency. If...such a construct will be silenced in subsequent generations. You will know if you obtained a transformant...
  9. CRISPR 101: Ribonucleoprotein (RNP) Delivery

    Type
    Blog Post
    Published
    Sept. 6, 2018, 12:02 p.m.
    ...enhanced the ability of scientists to make genomic alterations, bringing about a revolution in genome engineering...engineering applications of CRISPR including: generating single or multi-gene knockouts in a wide variety...editing using homology directed repair (HDR), and generating large genomic deletions. What are the advantages...and specificity is a concern, such as knockout generation or homologous recombination.  However, experiments...step in this type of CRISPR experiment is the generation of the RNP complex.  While one option is to purchase...in vitro transcribed from ssDNA, which can be generated by commercial vendors such as IDT. These two components...electroporation (A in the figure above), which generates pores in the cell membrane, allowing for entry...
  10. AAVs CREATed for Gene Delivery to the CNS and PNS

    Type
    Blog Post
    Published
    Sept. 28, 2017, 2:01 p.m.
    ...neurons throughout the whole brain. Neurons of the peripheral nervous system (PNS), which connect the heart...mutant AAV capsid (cap) expressing plasmids is generated. Diversity is introduced into the cap plasmid ...was neurons and astrocytes. Why screen for IV deliverable AAVs? Typically AAVs are directly injected into...transduction efficiency of neurons were measured. On average, AAV.PHP.eB and AAV.PHP.S had 1.5- to 2-fold higher...They also transduced a higher number of neurons overall (GFP+ cells that also stained for a neuronal marker...labeling of neurons, because it doesn’t require the generation of a transgenic mouse. 2. Cell-type-specific...translational applications (mechanistic studies and gene therapy treatments for neurological diseases). The Gradinaru...
  11. Interview: Hodaka Fujii on enChIP, New CRISPR Tools, and More

    Type
    Blog Post
    Published
    Dec. 2, 2014, 7:23 p.m.
    ...technology and its advantages? Fujii: In the last several years, my lab has been working on development of...specific genomic regions while retaining molecular interactions. For this purpose, we developed the insertional... regions. I believe that enChIP will markedly accelerate research of regulation mechanisms of genome functions...some of its potential applications? Fujii: We generated a series of retroviral vectors expressing tagged...biological systems. We are currently developing several additional systems of enChIP to make the technology...to journals. In addition, it is my pleasure to interact with my colleagues in meetings of scientific societies... Rhine River. In the US, I very much enjoyed interactions with many excellent colleagues at NYU and visiting...
  12. Fluorescent Proteins 101: Green Fluorescent Protein (GFP)

    Type
    Blog Post
    Published
    May 15, 2014, 3:33 p.m.
    ...implantation and generation of transgenic mice. Purification: GFP can be used as a general epitope tag for...biosensor or cell marker, studying protein-protein interactions, visualizing promoter activity, and much more...fluorescent activity; very little truncation is tolerated, however, point mutations are acceptable. GFP'...mutations have since been introduced to GFP and new iterations of fluorophores are constantly being engineered...energy transfer (FRET): This is used to study the interactions between two proteins or between two domains ... has also been used to study protein-protein interactions. In this case, two portions of EGFP are fused... their activity and visualize the effects of alterations to this activity. Learn more about optogenetics...
  13. With an Eye Towards the Future, We Look Back at the March for Science

    Type
    Blog Post
    Published
    Oct. 24, 2017, 1:54 p.m.
    ..., the legacy of each government and generation is in the veracity of its work. Alina Chan is a postdoctoral...these mistakes quickly. However, many scientists operate in a hyper-competitive environment where getting...speak out in unprecedented force during the 2015 federal election.   Even as we marched in solidarity with... Washington, DC, USA 38.9072°N 77.0369°W – Mark Lucera I am a passionate scientist.  I care about my ...People asked, and we talked.  That's a win. Mark Lucera is a PhD trained scientist at the University of...Postdoctoral Association.  Follow him on twitter at @Mark_Lucera. Ann Arbor, MI, USA 42.2808°N 83.7430°W – Alexandra...Aurora, CO where she studies the development and regeneration of mammalian taste buds. Erin is also the President...
  14. CRISPR-based Genome Editing Systems For Editing in E. coli

    Type
    Blog Post
    Published
    April 13, 2021, 1:15 p.m.
    ...pEcCas/pEcgRNA is superior in several ways: The pEcCas plasmid can be operated at 37 ℃ for faster growth ...plasmid that expresses the S. pyogenes Cas9, a temperature-sensitive replicon for self-curing, an arabinose..., 2) changed the replicon of pCas into a non-temperature-sensitive replicon, and 3) added the sacB gene...containing BsaI restriction enzyme sites at its ends to generate pEcgRNA. The ccdB serves as a counterselection...genes of interest in BL21(DE3) using the newly generated pEcCas/pEcgRNA system.   Advantages of the pEcCas...directly ligated with the annealed 24 nt oligos to generate new pEcgRNA. pEcCas/pEcgRNA can be applied not... the gene dosage of glucose dehydrogenase and generated a strain that could achieve glucose dehydrogenase...
  15. Bacterial Toxin-antitoxin Systems as Molecular Biology Tools

    Type
    Blog Post
    Published
    Nov. 1, 2018, 12:35 p.m.
    ...more stable than the methyltransferase. When a plasmid is lost, the methyltransferase is degraded and/or...stabilized luciferase-expressing plasmids to examine in vivo-induced promoters in the Vibrio cholerae vaccine...ensure that plasmids are passed down through generations (Figure 1). These so called “plasmid addiction...composed of restriction endonucleases and methyltransferases. Restriction endonucleases cleave DNA at ...specific nucleotide sequences. To counter this, methyltransferases add methyl groups to bases at specific nucleotide...stably express antigens in sufficient quantities to generate an immune response. As a proof of concept, they...genes that couple host cell division to plasmid proliferation." Proceedings of the National Academy of Sciences...
  16. Viral Production at Addgene

    Type
    Blog Post
    Published
    Oct. 24, 2023, 1:15 p.m.
    ...preps and our lentiviral preps.   Viruses are generated using standard methods that have been optimized...optimized for each specific virus in order to generate high quality preparations. After production, all virus...the University of Pennsylvania Vector Core. In general, titering is performed by the facility that produced...suggests that titers obtained using ddPCR are generally two to three fold higher than those achieved using... us. Full sequencing of the Viral Genome Next-generation sequencing is performed on viral genomes isolated...items) are produced in 293T cells using the 2nd generation psPAX2 and pMD2.G packaging system developed ...lentiviral preparations (“-LVC” catalog items) are generated from lentiviral preparations (described above)...
  17. CRISPR 101: Any Base Transversion Editors

    Type
    Blog Post
    Published
    April 1, 2025, 1:15 p.m.
    ... developed, though, researchers at HuidaGene Therapeutics guessed that fusing MPG to an ABE would allow...transversion editor AYBEv3. This tool still retained considerable A → G editing activity at most sites, in addition...they co-expressed Polη, a translesion synthesis polymerase known to preferentially incorporate A bases across... N108Q mutation in the deaminase), produced an average A → C product purity of 48%. Like CGBEs, these ...abasic site before filling the empty space. Over several rounds of rational mutagenesis, the team progressed...allow it to recognize thymine (T) or cytosine (C). Several different teams succeeded with this approach around...recognize T and/or C substrates. The HuidaGene Therapeutics team has deposited their editors, called gTBE...
  18. Advancing Biology with Zebrafish: Genetic Tools for Developmental Studies and More

    Type
    Blog Post
    Published
    Aug. 13, 2019, 12:58 p.m.
    ...processes from development to metabolism to fertility. Several zebrafish-specific gene expression databases that...available, new hypotheses about specific genetic interactions arise and tools to deactivate specific genes...way to deactivate genes without spending months generating mutants. Unexpectedly, phenotypes sometimes differ...of gene regulation (El-Brolosy et al., 2019). Generating zebrafish transgenics Creating transgenic organisms...different experimental conditions. Strategies for generating transgenic zebrafish are well established (Felker...cell RNA sequencing approaches (Harland, 2018). Several different methods have been developed, relying ...i.e., redundant) genome, their long three-month generation time and labor-intensive maintenance compared...
  19. Viral Vectors 101: Parts of the AAV Packaging Plasmid

    Type
    Blog Post
    Published
    Dec. 3, 2020, 2:15 p.m.
    ...Virus Genome Interactions Important for Vector Production and Transduction. Human Gene Therapy 31:499–511...and Rep40) Rep proteins. Alternative splicing generates the different C-terminal regions of the Rep proteins...transfer plasmid, which contain regions of dsDNA. To generate a 3’ hydroxyl group needed for DNA replication...in the ITRs, uses its endonuclease activity to generates a ssDNA substrate which is then nicked by its ...splicing and differing translational start sites generate the three VP proteins. The three VP proteins assemble...Adeno-Associated Virus (AAV) as a Vector for Gene Therapy. BioDrugs 31:317–334 . https://doi.org/10.1007/...Improving the Efficacy of AAV Vectors. Molecular Therapy - Methods & Clinical Development 12:248–265 . https...
  20. Fostering communication in remote collaborations

    Type
    Blog Post
    Published
    April 21, 2020, 1:14 p.m.
    ... replicates how you’d interact with team members in person, and improves overall communication.  Maintain...project and accelerates the pace at which problems can be addressed and new ideas generated. Furthermore...team in Paris, France. While efforts like these accelerate the progress of research, they can also present...different tasks. But these challenges can be exaggerated when communicating across time zones, digitally...the times that work best for them. This also accelerates the pace of research by circumventing the slower...exchange project at the International Cancer Immunotherapy Conference in Frankfurt, Germany When funding...
Showing: 221 - 240 of 822 results