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  1. Mouse Modeling, Part 2: Breeding and Crossing Mice

    Type
    Blog Post
    ...commonly used to introduce multiple mutations. This is because as more mutations are introduced into a single...arise when crossing mice with multiple mutations is if the mutations are on the same chromosome. Homologous...engineering should be used to separately introduce each mutation independently into different mice, and then these...production of offspring that have a combination of the mutations engineered into each of their parents. Here’s ...mice that are each homozygous for one of the two mutations that you want combined in your offspring. Genotyping...producing mice with your desired combination of mutations. Assuming your parental mice were all homozygous... to a mouse that is homozygous for a different mutation, the F1 offspring will be either hemizygous or...
  2. Plasmids 101: Colony PCR

    Type
    Blog Post
    ... about the orientation of the insert Orientation-Specific Tells you the orientation of the insert... provide information about the orientation of the insert. Orientation-specific primers: If you need ...information about insert orientation, then you might consider designing orientation-specific primers. Blunt...primers, 2) backbone-specific primers, and 3) orientation-specific primers.       Insert-specific primers...insert is present but not if it’s in the correct orientation or even if it’s in your plasmid backbone. Backbone-specific...an example of when you might want to know the orientation of the insert. One member of this type of primer...or no" test results Doesn't tell you the orientation of your insert or if the insert is in your plasmid...
  3. An “elegans” Approach to Better CRISPR/Cas9 Editing Efficiency

    Type
    Blog Post
    ...dominant mutation, known as co-conversion (Arribere et al., 2014). In both cases, the selected mutation must...repair of a lethal mutation should remove much of the unedited “haystack”, facilitating recovery of edited... of lethal mutation co-selection. Only animals rescued for the conditional lethal mutation survive the...determined optimal PAM orientation for editing using two Cas9 targets. An orientation where the 5’ ends of...Cas9 allows us to delete sequences and introduce mutations and epitopes with unprecedented ease. These new... homozygous, outcrossed knock-in ready for experimentation. In 2014, several manuscripts published in ...approach relying on repair of a conditional-lethal mutation to identify edits with minimal screening effort...
  4. Treating Muscular Dystrophy with CRISPR Gene Editing

    Type
    Blog Post
    ...models with mutations in human-relevant exons 45-55, rather than in the traditional exon 23-mutated mouse model... genetic diseases, the mutational landscape is broad and varied, necessitating the development of many...modification, to repair or add in disease-causing mutations, but, until recently it hadn’t been used to treat... males. DMD is caused primarily by frameshift mutations in dystrophin, a protein essential for proper ...sequence appears to be nonessential. Within the mutational hotspot for dystrophin, exons 45-55, there are...partially functional protein. Individuals with these mutations are often asymptomatic, or have only mild symptoms... oligonucleotide exon skipping (OEN) to remove mutated exons from the dystrophin transcript. Unfortunately...
  5. CrispyCrunch: High-throughput Design and Analysis of CRISPR+HDR Experiments

    Type
    Blog Post
    ...Optimal mutation in-depth One the most sophisticated features of CrispyCrunch is how it mutates guide sequences...region, the mutation may cause side-effects. Further, work by John Doench et al. shows that mutating a single... After each mutation, it will check the CFD score. If it is below 0.03, it stops mutating. (Note: the ... example, it ranks guides by CFD score, and it mutates HDR donor templates to avoid re-cutting when needed...for TagIn. HDR requires the additional step of mutating guide sequences in a way that prevents re-cutting...do it best. Scientists are typically advised to mutate the PAM to which the guide binds. However, if the...implemented the following algorithm for optimal mutation in CrispyCrunch: If the guide PAM resides outside...
  6. Chemogenetics Guide

    Type
    Guide
    ...? blog! Studies of GPCRs led to development of mutated receptors that while unresponsive to endogenous...experimental setup) were not possible. To overcome this limitation, the inhibitory KORD DREADD was developed to ...PSEMs). PSAM domains were first named for the mutations that allowed them to respond to their cognate ...anti-smoking drug varenicline. This PSAM carries mutations at L131G, Q139L, and Y217F and is termed PSAM4...RHJ, DiBerto JF, et al. (2015). A New DREADD Facilitates the Multiplexed Chemogenetic Interrogation of...
  7. Using CRISPR/Cas9 to Edit Disease Out of the Genome

    Type
    Blog Post
    ...developing anti-CRISPR proteins aid the limitation of these mutations, to control the CRISPR system activity...could be used to edit several autosomal-dominant mutations that have been connected to the early onset of... CRISPR/Cas9 corrects Alzheimer’s disease mutation in basal forebrain cholinergic neurons derived...Academy of Sciences found that mice with a dominant mutation in a gene that causes cataracts could be rescued...demonstration of use of genome editing to correct point mutations in two diseases with real phenotypic effect.” ...noted that CRISPR/Cas9 has been used to generate mutations in a wide range of organisms, but its potential...phase of crisis where they 'collect' a number of mutations.” Cystic fibrosis may not be the most likely candidate...
  8. Data Freedom: The Expansion of Data Sharing in Research Publications

    Type
    Blog Post
    ...inappropriate statistical methods, omission of some data, etc.  The firestorm that followed implementation of the...condensed into a statistically evaluated set of values.  However, to evaluate the interpretation of the experiment...Instead, selected images are said to be representative or the statistical variation is calculated and placed...overnight revelation, rather it was the result of consultations between researchers and publishers. Nonetheless.... The PLOS policy on data access is a formal statement that is already practiced or required by many ...means that supporting datasets must be logically annotated and arranged, as in an actual publication and ...efficient science. Improvements in our discipline for annotation and archiving of data are likely to improve research...
  9. Harnessing Bacterial Toxins for Allelic Exchange

    Type
    Blog Post
    ...astounding number of ways to create chromosomal mutations in bacteria, so many that it may be difficult ...path to take. A quick and easy way to introduce a mutation in the chromosome is to disrupt expression of ...genes. However, there are ways to create scarless mutations, ones that don’t leave any undesired scars in ...technology has also aided in the creation of scarless mutations, both in stand-alone systems (Jiang et al., 2013...plasmid curing steps, and can generate off-target mutations. Modifying bacterial genomes using counter-selectable...is frequently called allelic exchange. Here, a mutated allele introduced from a conjugative plasmid replaces...versatile technique, and is less prone to off-target mutations. Ultimately, successful allelic exchange requires...
  10. Fluorescent Proteins 101: When GFP lets you down

    Type
    Blog Post
    ...number of limitations that you may run into if you choose to use it. Several of these limitations and possible...protonated and a deprotonated state (Tsien, 1998). The deprotonated state has an absorbance maximum around...protonated state, however, does not absorb light at 488 nm. The ratio between the two states is reflected...encoded probe, but there are limitations. Being aware of the limitations is important for the successful...mEGFP. This variant was made by introducing two mutations (F64L, S65T) in the original jellyfish GFP (AvGFP...with improved brightness (Tsien, 1998). Another mutation (A206K) is necessary to generate the strictly ...autofluorescence is less of a problem when the excitation wavelength is shifted to longer wavelengths. ...
  11. Donations from Addgene to Yield Answers for Rare Disease Researchers

    Type
    Blog Post
    ...understand Lowe Syndrome, a devastating genetic disease caused by mutations in the OCRL1 gene that leads...different mutations in a gene called SOX10. To understand the functional role of those mutations, they now...to work to explore the effect of various OCRL1 mutations on cell behavior in greater detail. The goal is...sensitive to sunlight and prone to developing metastatic melanomas and other cancers. Joshua Wang (bottom...CRISPR-Cas9 constructs from Addgene to gene-edit mutations into XP genes and other genes involved in photosensitivity...plasmids to explore the functional differences among mutations responsible for the disease known as Alternating...the brain. McSweeney says they now think that mutations in the gene may prevent neurons from returning...
  12. How to Write a Scientific Review Article

    Type
    Blog Post
    ... mentioned, I also added citations in real time as I wrote, so each statement was referenced even in the...studies that reported mutations in that protein (including how frequently a mutation was found and the size...review Once you start reading, there will be a temptation to include every piece of information that was...review articles Whether submitting a review by invitation or by your own accord,  once you have these rules... write, meaning I use the software to add the citations in real time as I write. Things are going to get...from the beginning. I also recommend using the citation style of (Last name, Year) in the document while...experiments. Later, you can easily convert the citation style to whatever the journal requires. Using ...
  13. Rett Syndrome: A History of Research and Therapeutic Outlooks

    Type
    Blog Post
    ...Syndrome research. With a shared passion for facilitating research and discovery, Addgene and RSRT have...approaches. What is Rett Syndrome? Caused by a mutation in the methyl-CpG binding protein 2 (MECP2) gene...Zoghbi's lab discovered the first disease-causing mutations in the MECP2 gene leading to Rett Syndrome (Amir... regulate transcription (Baker et al., 2013). Mutations that affect this interaction to varying degrees...determine the clinical severity of different MECP2 mutations. More recently, the Bird lab found that only a... human MECP2 locus and MECP2 protein, showing mutations corrected by CRISPR/Cas9 in wild-type human iPSCs... exciting and promising results for repairing mutations in models of neurological disease. Klaus Rajewsky...
  14. Pushing the Limits of DNA Assembly

    Type
    Blog Post
    ...primers with your desired mutation, performing PCR to generate the mutation and linearizing your vector... limit to where the mutation can be placed. With other techniques, when mutations are spaced farther apart...multiple synthetic fragments, create multiple mutations in one or multiple fragments, and generate constructs... Generation of constructs with multiple point mutations Cloning sgRNAs Production of Yeast Expression ...Cassettes Generating constructs with multiple point mutations NEBuilder HiFi can simplify multi-position site-directed...assembling multiple fragments containing the desired mutations. This same process can be used simultaneously ...simultaneously for the generation of one or more mutations – it is as easy as obtaining a plasmid with the gene of ...
  15. Deep Dive: qPCR

    Type
    Blog Post
    ... differences of twofold or greater with good statistical significance (Taylor, 2017). With the right conditions...different efficacies DART-PCR No Raw Data Statistically defined log-linear phase   Table 2: ... them back before reporting the data!   Statistical analysis  Getting your RQ value isn’t the end...your analysis process. You’ll still need to do statistical analysis to determine if there are any significant... Yuan, 2006 has a good overview of different statistical analysis methods that pair well with slightly...step, remember we here at Addgene frown upon statistical laxness in all its forms. Reporting your data...provide you with the highest form of flattery - imitation! Use the MIQE guidelines (Bustin, 2009) to ensure...
  16. March for Science

    Type
    Blog Post
    ...select your state. State Legislatures: To find the website to contact representatives at the state level you...based on our most accurate interpretation of the world, and this interpretation should not effected by claims...contact your representatives in case you would like to talk with them about science: Representatives: To find...contact information for your representative in the House of Representatives all you need to know is your...march in Washington, D.C., the seat of the United States government? Politics and science are intrinsically... you can click on your state in this map. Finally, the march is meant to inspire scientists to be more...Center: The Politics of Climate Change in the United States CNBC: Kellyanne Conway: “I”m not in the job of ...
  17. CRISPR 101: Making a Knock-In Cell Line

    Type
    Blog Post
    ...frameshift mutation. The majority of cellular repair events will generate these types of mutations, making...recognition sequence is destroyed via mutation. By introducing a mutation in either the PAM or the guide recognition...mishaps in this class of genome edit. Knock-in mutations and gene editing Targeted genome editing events... this is not the case for knock-ins. Knock-in mutations typically require an exact DNA sequence to be ...cells. It is important to know that HR is often mutated in cancer cells, specifically in breast and ovarian...recommended you check your cell lines for HR-related mutations before attempting knock-ins by HDR.   ... with some success (Yu et al., Nat Chem Biol). Mutate the PAM or sgRNA sequences Cas9 likely goes through...
  18. Fluorescent Proteins 101: Monitoring Cell Mobility Using Fluorescent Proteins

    Type
    Blog Post
    ...information regarding immune cell mobility than the static microscopy images of chemically coloured lymphoid...source is mounted above (epi) the specimen and the excitation light passes through the microscope objective... or dyes. 3. Two-photon microscopy Two-photon excitation microscopy is a fluorescence imaging technique...fluorescent molecule (see figure to the right). The excitation generated by these two-photons occurs only at...immunologists the ability to count cells and statistically analyze cell movements. By using cells labelled...diverse tissue environments. These studies provide quantitative measurements of cellular motility, interactions...understand what is going on in the body at steady state or under physio-pathological challenge. However ...
  19. 7 Tips to Secure a STEAM Internship This Summer

    Type
    Blog Post
    ...their leadership status in their current field of expertise augments their authoritative voice. Send a draft...share a common set of criteria such as citizenship status, academic year, and grades that serve as automated...can be found on the Addgene blog.   3. Personal statement brilliance In addition to sending in a cover letter...letter, you are always asked to draft a personal statement, which is the perfect opportunity to paint a comprehensive...devoting some time to writing a solid personal statement will pay dividends. This is the only opportunity...tools that can help you craft a solid personal statement.  4. Letters of recommendation wisdom  Reach out...for the character you painted in your personal statement. Make certain to choose your recommenders based...
  20. Plasmids 101: Blue-white Screening

    Type
    Blog Post
    ...complements the mutation allowing for a functional enzyme. This process is called α-complementation. The system...β-galactosidase enzyme through α-complementation (cell B). As shown on the representative plate to the right, colonies... that deleting a section from the lacZ gene (a mutation called lacZΔM15) creates a non-functional β-galactosidase... inserted it into a plasmid, creating an α-complementation cloning vector. When a cloning reaction goes...will not complement the cell's β-galactosidase mutation. An unsuccessful cloning reaction leaves the α-peptide...initial overnight incubation increases pigment precipitation, enhances the blue color of negative colonies...proper E. coli strain (i.e. contains the lacZΔM15 mutation): XL1-Blue, DH5α, DH10B, JM109, STBL4, JM110, ...
Showing: 161 - 180 of 836 results