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  1. Finding Your Science Policy Path

    Type
    Blog Post
    ... diplomacy and international relations, advocacy, and writing legislation (see Figure 1 for career map... give advice and guidance to those that ask. Relationship building is key in science policy. Luckily, ...happy hours that you can attend to help build relationships.  Reach out to a science policy professional...can manifest via research and data gathering, regulatory efforts, policy implementation, program management... It occurs in a government setting: drafting legislation, making rules, and implementing the policy within...company who decides how they are going pursue regulatory approval for a new product or a well-endowed ...But some are also open to individuals from mid- to late-career backgrounds. In fact, many of my AAAS STPF...
  2. Antibodies 101: Validation

    Type
    Blog Post
    ...despite the manipulation. Additionally, not all sample types are amenable to genetic manipulation, nor can...your target then you would expect to see good correlation between the levels of target detected in both...both methods. These approaches have relatively low sensitivity, which can be problematic if you are trying...need to be aware of any possible alternative translation start sites or alternative splicing that could...also influence antibody binding by altering the relative concentration of potential antibody binders and... targeting a different epitope, and look for correlation between the results. Using antibodies against...cytometry using both antibodies, as well as a third unrelated antibody as a negative control (A). The two antibodies...
  3. Human Germline Editing Using CRISPR

    Type
    Blog Post
    ..., and electroporated them with an ssODN repair template in induced pluripotent stem cells made from the...fertilization. Since Ma et al. designed a repair template with two synonymous mutations to distinguish it...were able to distinguish between repair from the template vs repair from the maternal MYBPC3 allele. Interestingly...from the single-stranded oligonucleotide (ssODN) template supplied by Ma et al., but instead from the mother...repair proceeded through NHEJ rather than HDR. In later characterization studies, the edited embryos proceeded...embryos to undergo editing using the provided ssODN template. In fact, this finding led the authors to title...proceed with caution and with proper oversight from regulatory and ethics committees comprised of individuals...
  4. Genome-wide Screening Using CRISPR

    Type
    Blog Post
    ...screening experiment is to generate and screen a population of mutant cells to identify genes involved in...experiments commonly use lentivirus to deliver a pooled population of gRNAs to Cas9 expressing cells. Pooled lentiviral...CRISPR libraries”) consist of a heterogeneous population of gRNA-containing lentiviral transfer vectors...the CRISPR library to generate a heterogeneous population of mutant cells, with each cell or set of cells...distribution is analyzed in the drug-resistant population compared to a non-treated control group. In this...maintaining the distribution of each gRNA within the population is key. Loss of representation due to enrichment... sufficient representation within your mutant population requires a massive amount of cells as starting...
  5. Plasmids 101: Modular Cloning

    Type
    Blog Post
    ... cellular behaviors requires making complex manipulations to cells. For example: in a cell there are proteins...other proteins and with DNA, and these complexes regulate the transcription of specific genes. What if one... one of those genes coded for a protein that regulated its own transcription, or the transcription of ...These interactions yield a cellular phenotype, translational output, etc., which can support a larger cellular... is made, modified (sometimes many times), and isolated afterwards. To engineer these production pathways... them to these organisms via another optimized platform. Gene Stacking As the name implies, gene stacking...identify the best cocktail of genes when the relationship between genotype and phenotype is best described...
  6. Adenoviral Vector Production and Troubleshooting

    Type
    Blog Post
    ... and then stained 10 days later. Plaques are counted and titer is calculated in terms of plaque forming...medicine (2017).   1st Gen AdVs are stripped of regulatory genes E1 and E3. Without these genes, AdVs cannot...8.2 kb, and in vivo transgene expression ceases relatively quickly due to immune response against AdV. Importantly...low titer rAdV-S, and can be stored at -80C for later use or used immediately for amplification.*Pro-Tip...not use CsCl are commercially available. Titer calculation (1 or 10 days) Physical titer (particle count...260nm corresponds to 1.1 x 1012 particles/mL. To calculate the particle number: OD260 reading x dilution ...
  7. Rabies and Neuronal Tracing

    Type
    Blog Post
    ...the jobs they perform. This became foundational later on when we studied biological processes, like how...selectively infect a genetically defined cell population. While the EnvA genetic sequences are supplied...complex control of specifically defined neuronal populations. In one study, RABV monosynaptic tracing was ...neurons came from nearby neurons. It wasn’t until later time points that longer-range connections were seen...identify inputs to two major dopaminergic cell populations in two specific brain regions (Watabe-Uchida ...differences in the inputs to each of the two populations could be used to explain the differences in the... the functions of these two neuronal populations. Overall, this study laid the foundation for how different...
  8. Educational Planarian Tools for Teaching Developmental Biology Techniques

    Type
    Blog Post
    ...activity or their translation disrupted through physical blocking of the translation machinery. In the...gene expression and functions of key regeneration-related genes in four inexpensive and commercially available...transcription to create dsRNA. Students can produce DNA templates via PCR off of the same plasmid and use these ...expression changes through time or after genetic manipulation. The technique involves using synthetically ...create synthetic riboprobes off of linearized DNA templates which they can easily generate off of a circular... was first discovered and characterized in an unrelated worm (C. elegans) [2]. Delivering dsRNA matching...
  9. Pooled Library Amplifications

    Type
    Blog Post
    ...liquid media or solid media (on plates). In general, amplification on plates can help to ensure that diversity... anywhere from 10 ng to 1 μg of DNA. It often correlates with the size of the library, but generally needs...transformation efficiency, or more specifically calculated based on the size of and weight of your library...library varies significantly in plasmid size). On plates, each transformed bacteria will be its own colony...Screening Zhang Lab - Multiplexed Overexpression of Regulatory Factors (MORF) Library 3,548 250 - 10,000...Screening Rinehart Lab Iterative Synthetically Phosphorylated Isomers (iSPI) Libraries ~11,000–110,139 ...
  10. Plasmids 101: Knockout/Knock-In Plasmids

    Type
    Blog Post
    ...homologous recombination using a repair template. These templates can include loxP sites to create conditional...recombination. The concept is simple: deliver a template with a modified version of the targeted sequence...sequence to the cell which will recombine the template with the endogenous gene. Here, we'll describe the ... one of the homology arms. When we select cells later, we will first perform a positive selection for ...selection for the negative selection marker - this latter step will kill off many of the cells that have ...knockout targeting vector designed to insert and later remove a resistance gene. In this construct, the...
  11. Hot Plasmids and Viral Preps - May 2021

    Type
    Blog Post
    ...VP1, which self-assembles into a compartment encapsulating the protein of interest (Figure 3).   ...D-glucaric acid biosynthesis. This MPyV system encapsulated a rate-limiting enzyme in this pathway (myo-... of the protein compartment. Yeast with this encapsulated enzyme produced 20% more D-glucaric acid, suggesting...system can improve metabolic pathway yields by encapsulating a single enzyme. Compared with previous research...captures rare clones that represent 0.001% of the population.  Because indel generation by Cas9 can occur ...steady rate, scientists found a way to use the accumulation of indels to measure time. These plasmids with...ready-to-use viral preps with more on the way. S5E2 regulatory element containing vectors developed in the Jordane...
  12. Fluorescent Tagging of Endogenous Genes with SapTrap

    Type
    Blog Post
    ...individually generate gRNAs and homology arm repair templates containing the tag for each insertion. Also, it..., as well as the 5’ and 3’ homology arm repair template (Fig. 1, Step 1). There is no need for PCR or ...the second site accepts the homology arm repair template. SapTrap includes a prebuilt donor plasmid library...be used to generate functionally unique repair templates. A final ligation reaction correctly assembles...genetic locus, the toolkit also offers repair templates for tagging proteins in a tissue specific manner...of auxin to the culture medium. Any number of regulatory sequences, including protein enhancers and repressors...repressors, can be included in the repair template for inducible alteration of protein expression levels...
  13. Quick Guide to Working with Drosophila Part 1: Getting Started with Flies

    Type
    Blog Post
    ...exciting directions. Drosophila are very easy to manipulate genetically and have limited genetic redundancy...faster but are also more stressed by the heat. Isolating male and female flies Differentiating male and...make genetic crosses properly, it is important to isolate females from males while they are still virgins...genomes Compared to humans and mice, flies have a relatively simple genome. They have four chromosomes: the...are miniscule, so researchers generally do not manipulate them. Essentially, the X, second, and third chromosomes... phenotypes, check out the Classical Genetics Simulator website. One interesting thing to know is that... systems. Some resources will direct you to the latest information about gene function, while others offer...
  14. Mobile-CRISPRi: Bringing CRISPRi to Diverse Bacteria

    Type
    Blog Post
    ...that grew on a selective plate versus the number that grew on a non-selective plate. Most bacteria tested... types of bacteria: lab-adapted, environmental isolated, and disease-associated. Mobile-CRISPRi: a modular...glmS gene in the recipient's genome. Antibiotic plates lacking DAP select against donor bacteria and for...including pathogenic strains and environmental isolates. For example, Peters and colleagues used Mobile-CRISPRi...aeruginosa) in addition to Vicrio casei, a bacteria isolated from cheese. Knockdown efficiency, as measured... 100-fold excess of wild-type bacteria and the relative frequency of each of the 40 library strains was...
  15. Tips for Screening with Yeast Two Hybrid Systems

    Type
    Blog Post
    ... for screening protein-protein interactions. In later years, improvements to yeast transformation protocols...can either be applied to the bait in a single population (e.g. transforming both fusion plasmids, or mating... strain for screening), or arrayed on a 96 well plate where each well contains a defined prey fusion.  ...former allows for screening greater numbers, but the latter eliminates the step of identifying prey proteins...protein expression and correct folding, post-translational modification, protein degradation, access to...problem is that your proteins are not post-translationally modified, co-expression of the enzyme responsible...transcription-activating function of a eukaryotic regulatory protein. Science. 1986; 231:699-704. PubMed PMID...
  16. Sharing Your Lab Protocols: Using Apps to Save Time & Track Your Experiments

    Type
    Blog Post
    ... to copy and modify templates (e.g. http://openwetware.org/wiki/Protocols/Template). Nature Protocol Exchange... up after trying out the new protocols.io beta platform for sharing, annotating, and storing life science...molecular cloning protocols, including making LB agar plates, restriction digest of plasmid DNA, and bacterial...bacterial transformation. And more plasmid-related educational resources can be found in our Plasmids 101 blog...creating and editing Wikipedia pages, OWW will be relatively easy for you to begin using. For the novice, ...the repository. These protocols show up on the related plasmid pages and can help scientists use these...
  17. Performing In Vivo CRISPR Screens Using the FITS Approach

    Type
    Blog Post
    ...in immune cells have identified many putative regulators of immunity. However, in vitro screens cannot... a Thy1.1 selectable marker to facilitate the isolation of modified cells; and (5) is compatible with ...conditions for a screen that assessed genes that regulate antigen-specific CD8+ T cell responses to a murine...responses to cancer. The screen recovered known regulators, such as Ptpn2, Pdcd1, and Zc3h12a, demonstrating...Moreover, the screen identified putative novel regulators of CD8+ T cell responses in tumors, demonstrating...Cancer and the Immune System: Deciphering the Relationship...
  18. Plasmids 101: Plasmid Incompatibility

    Type
    Blog Post
    ...within the cell. Most plasmids encode a negative regulation system involving antisense RNAs or iterons that...indirectly inhibit replication through inhibiting translation of replication machinery proteins, or directly...transcription is repressed and replication is downregulated. In the second model, termed the “handcuff” ...cases of compatible plasmids, different negative regulation systems control plasmid replication of each plasmid... the same origin of replication, the negative regulation system cannot distinguish between the different...different plasmids. The concentration of negative regulation system elements in the cell is artificially high...). However, more recent studies suggest that the late replication that occurs for some types low copy ...
  19. Viral Production at Addgene

    Type
    Blog Post
    ...Next-generation sequencing is performed on viral genomes isolated from the final AAV preparation. Sequencing results...of AAV preparations is assayed by comparing the relative stoichiometric ratios of the viral capsid proteins...SYPRO Ruby staining and the molecular weight and relative intensity of the viral capsid proteins are analyzed...Viral capsid proteins VP1, VP2, and VP3 are shown relative to the total protein present in the sample. ...are added to cells in culture. Three to five days later, cell cultures are inspected for sterility. Transducibility...-AAVrg) alone at 1.1E6 vg/mL, or both. Two days later, Cre-dependent GFP expression was detected with ...vectors consist of full particles (white arrowhead) relative to empty particles (black arrowhead). Scale bar...
  20. Antibiotic Resistance: An Old Solution but a New Problem

    Type
    Blog Post
    ...been battling for centuries. As such, resistant populations can arise very quickly following the tried and...showing bacteria evolve antibiotic resistance on a plate! Antibiotic resistance can arise, and has arisen...antibiotics These scenarios expose bacterial populations to antibiotics at unnecessary times, putting ...pressure on resistant bacteria to over-take the population and making them more difficult to treat in the...susceptible bacteria that will be more difficult to treat later. A similar situation can occur if you treat a bacterial...because scientists in the laboratory will need to isolate and grow whatever bacteria are causing the infection...before they can test for resistance. Growing and isolating the infecting bacteria can take 24 hours or more...
Showing: 341 - 360 of 945 results