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  1. Viral Vectors 101: Virus Safety

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    Blog Post
    ...cancer. These viruses need to be handled in a BSL-2 (or BSL-2+) lab and require additional safety measures.... BSL-1. In BSL-2 labs, eye protection is required any time you have to work with BSL-2 materials, such...respiratory diseases in humans, earning this virus a BSL-2 classification. Lentivirus (a type of retrovirus) ...recommended or required in BSL-1 and required in BSL-2 labs. When working with lentivirus, many organizations...sprayed into the air. For lentivirus and other BSL-2 materials, you’ll need to use aerosol-tight caps, ...percentage of the decontaminate to be used for BSL-2 waste, and of course, if you are working with a substance... viruses are more dangerous than others, and the same holds true for types of viruses generated in the...
  2. Deep Mutational Scanning with One Pot Saturation Mutagenesis

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    Blog Post
    ... that results in a polymerase error rate of up to 2% per nucleotide position. The “sloppy” PCR reaction...modifications: 1) increased concentration of Taq polymerase, 2) increased PCR extension time, 3) increased concentration...to synthesize a complementary mutant strand (step 2 and 3). Then the uracil-labeled template strand is...restrict site matter? Most of the time no, but there are 2 instances where it does. 1) When the backbone vector...ExoIII. See the below figure for an example like this. 2) When your gene of interest has a BbvCI site(s). If...saturation mutagenesis method are 1) ease of use, 2) time savings, and 3) ability to perform single site...PMID: 23766324. PubMed Central PMCID: PMC4409680. 2. Mccullum, E. O., Williams, B. A., Zhang, J., & Chaput...
  3. Screening for Successful Genome Editing with Digital PCR

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    Blog Post
    ...and wild type target in each sample can be quickly calculated (details in [2]) and can be used to quantify...resulting from non-homologous end joining (NHEJ) (2-5), depending on your desired genome edit. Since exploitation... have been reported for mismatch nuclease assays (2, 6, 7). Ability to distinguish between mono-allelic...assays, in addition to testing their performance (2). Remember that although digital PCR is a great screening...PMID: 24509632. PubMed Central PMCID: PMC4063274. 2. Findlay, S. D., Vincent, K. M., Berman, J. R. & Postovit... PCR Digital PCR (dPCR) involves splitting up a sample into thousands of physically isolated partitions...of target DNA molecules present in the original sample with a great deal of precision. This means digital...
  4. Finding nucleic acids with SHERLOCK and DETECTR

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    Blog Post
    ...to detect SARS-CoV-2 RNA. The test is started using RNA purified from patient samples and can be read using... can be used to diagnose the presence of SARS-CoV-2 RNA, but inadequate access to reagents and equipment...named this system SHERLOCKv2 for SHERLOCK version 2. Here are some of the improvements: SHERLOCKv2 uses...recently adapted the DETECTR platform to detect SARS-CoV-2 using a lateral flow strip format. They published ...CY (2020) CRISPR–Cas12-based detection of SARS-CoV-2. Nature Biotechnology. https://doi.org/10.1038/s41587... and Functional Characterization of Diverse Class 2 CRISPR-Cas Systems. Molecular Cell 60:385–397 . https...Cpf1 Is a Single RNA-Guided Endonuclease of a Class 2 CRISPR-Cas System. Cell 163:759–771 . https://doi....
  5. Plasmid Preps: Different Purity, Different Quantities, Different Uses

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    Blog Post
    ... be extracted from small bacterial cultures (i.e. 2-3 ml) with or without commercially available kits ...ratios measured at 260 and 280 nm should fall ~1.8 - 2 and give scientists an indication of purity versus...contaminants. The 260 and 230 nm ratios should fall ~2 - 2.2, and provide an indication of purity versus ...hydrochloride used during plasmid extraction. Figure 2: Use cloning grade DNA for direct cloning of your ...Not all plasmid preps are the same. Before purifying a plasmid from a bacterial culture, it is important...nucleic acid and chemical contaminants, these DNA samples must also be entirely endotoxin free. Endotoxin...
  6. AAV Titers: Where Do They Come From And What Do They Mean?

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    ...PubMed Central PMCID: PMC3640491. 2. Grimm, D., et al. "Titration of AAV-2 particles via a novel capsid ELISA...report the physical titer of a viral solution (Figure 2). Because physical titers are used for dosing purposes...mean and how they can be compared.   Figure 2: Label that comes on Addgene’s AAV aliquots. Our titer...of genomes can limit production of recombinant AAV-2." Gene therapy 6.7 (1999). PubMed PMID: 10455443. ...Characterization of a recombinant adeno-associated virus type 2 Reference Standard Material." Human gene therapy 21.10...each individual sample, this will reduce convenience and comparability because each sample with be quantified... low-concentration samples can also behave differently in PCR, even if both samples fall within the linear...
  7. Viral Vectors 101: Producing Your rAAV

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    ...digital PCR. Human Gene Therapy Methods, 25(2), Article 2. https://doi.org/10.1089/hgtb.2013.131 Lock,...Pawlita, M., Ferrari, F., Samulski, R., & Kleinschmidt, J. (1999). Titration of AAV-2 particles via a novel... virus Once you have transfected your cells, wait 2–5 days and then collect the supernatant and/or producer...quantification of adeno-associated virus serotype 2-derived inverted terminal repeat sequences. Human ...of genomes can limit production of recombinant AAV-2. Gene Therapy, 6(7), Article 7. https://doi.org/10.1038...Characterization of a recombinant adeno-associated virus type 2 Reference Standard Material. Human Gene Therapy, 21...known titer on every qPCR run. Note that the rAAV sample has to be digested with DNase before undergoing...
  8. Plasmids 101: Secondary Nanobody Toolbox

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    Blog Post
    ...antibody has an antigen binding site for a total of 2 binding sites per antibody. C) IgG’s are big enough...enough that multiple labels (green circles in figure 2 below) can be attached to each antibody. But being...displacement Require separate incubation of 1° and 2° Must use different species and/or different IgG ...Greater resolution due to lower label displacement 2° incubation can be skipped by pre-binding to 1° ...a fluorescent tag and the target antigen to about 2 nm, which can lead to higher resolution for super-...subclass.   Express the Nanobody In Bacteria: Table 2 also has a link to the plasmid you’ll need to express... Find plasmids from this publication at Addgene. 2. Bates, M., Böhning, M.I., Chug, H., Görlich, D., ...
  9. Viral Vectors 101: Pseudotyping

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    Blog Post
    ...safely. Recently, many SARS-CoV-2 researchers began pseudotyping the SARS-CoV-2 spike protein into a lower ...SARS-CoV-2 virus. Scientists have been using similar pseudotyping methods with other viruses in a BSL-2 lab... et a., 2018).   Figure 2: To pseudotype with the SARS-CoV-2 spike protein, scientists encode...production uses three plasmids: (1) The transfer plasmid, (2) the envelope plasmid, and (3) the packaging plasmid...example, production of vesicular stomatitis virus, HIV-2, and human foamy virus in cell lines expressing galactosyl...for Pseudotyping Lentiviral Particles with SARS-CoV-2 Spike Protein for Neutralization Assays. Viruses 12...Are Inactivated by Human Serum. Molecular Therapy 2:218–222 . https://doi.org/10.1006/mthe.2000.0116 Gutierrez-Guerrero...
  10. Viral Vectors 101: The Retroviral Lifecycle

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    Blog Post
    ...that have been developed into retroviral vectors and 2.) a subclass of retroviruses called the lentiviruses...effectively. Retroviral structure   Figure 2: Structure of a retrovirus. Image re-used from Dong...Dong & Kantor, 2021 under CC-BY license. Figure 2 gives a detailed view of the structure of a retroviral...transfer of RT, which would actually occur in step 2 during uncoating. After uncoating, reverse transcription...one of the two strands’ DNA counterparts from step 2 will be integrated by the viral integrase protein ... Air. Environmental Science & Technology Letters, 2(4), 84. https://doi.org/10.1021/ACS.ESTLETT.5B00050...instructions in the same producer cells as the virus. Because it is made at the same time as the other ...
  11. Plasmids 101: Dimers and Multimers

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    Blog Post
    ...identification.   Fig. 2: Gel image of Plasmid 61564: pBAMD1-2 (~4.7 kb) digested with SpeI and... at ~3.6 kb and ~1.1 kb (lane 3). Uncut DNA (lane 2) has a band at <3 kb, which corresponds to the supercoiled...formation of plasmid multimers. Cell. 1976 Dec;9(4 PT 2):707-16. doi: 10.1016/0092-8674(76)90134-3. PMID: ...dimers in Escherichia coli K-12. Plasmid. 1989 Mar;21(2):138-41. doi: 10.1016/0147-619x(89)90057-7. PMID: ...Plasmids and Chromosomes. Microbiol Spectr. 2014 Oct;2(5). doi: 10.1128/microbiolspec.PLAS-0025-2014. PMID...Behavior of Plasmid DNA. Microbiol Spectr. 2015 Apr;3(2):10.1128/microbiolspec.PLAS-0036-2014. doi: 10.1128...plasmid monomer from a plasmid sample, or if no monomers exist in your sample, you could try linearizing ...
  12. Flow Cytometry Readouts: Yes, No, and Everything in Between

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    Blog Post
    ...low expression, and everything in between (Figure 2). These smears tend to occur when you are looking ...based on your experiment. You can see from Figure 2 that determining where to place your gate based on...the dot plot would be complicated.  Figure 2: (A) a smeary dot plot showing a range of antibody...plot in Figure 4 compared to the dot plot in Figure 2. Quantification using MFI makes it easier to identify...105 signal intensity. If your samples and controls were processed the same way, the GFP- population should... control (left) or with the sample (right). Negative and positive samples are clearly distinguishable ...designed your first flow panel, you’ll load your samples into the cytometer and see one of two results for...
  13. Important Considerations When Using AAVs

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    ...University of Manitoba due to their Biosafety Level-2 or 2+. Please Note: Despite the fact that AAVs themselves...long and stable expression (up to 9 months in mice [2]). Low Immune Response: Compared to other viral vectors... location. Location (1): What tissue? Location (2): Where in the tissue/which cell type? Location (3...may be sufficient to overcome the transport issues. 2. Failure to plan (for storage) Is planning to fail...Find Ready-to-Use Retrograde AAV Preps at Addgene 2) Comparison of genetically engineered receptors (i.e...Therapy 15.10 (2007): 1740-1743. PubMed PMID: 17882145. 2. Zincarelli, Carmela, et al. "Analysis of AAV serotypes... tropism and axonal transport of AAV serotypes 1, 2, 5, 6, 8 and 9 in the mouse brain." PloS one 8.9 (...
  14. Fluorescent Proteins 101: Photoactivatable Fluorescent Proteins

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    Blog Post
    ...fluorescent state make them useful for 2-color imaging with green PA-FPs. Table 2: Properties of Selected Reversible... conventional FP imaging. PA-FPs are divided into 2 main categories - those with irreversible and reversible... forms of the chromophore which contribute to the 2 peaks of wtGFP’s excitation spectrum- a major 397 ... / N99K / S148L / I165V / Q167P / L169V / I203R) (2) and PA-mRFP1(S146H / I161V / I197H) (3) were derived...with two distinct wavelengths of light (see Table 2). The best known reversible PA-FP is the naturally... above background. The majority of PA-FPs come in 2 flavours- monomeric and tetrameric. Tetrameric PA-...most PA-FPs, but, in 2015, the Looger Lab designed 2 variants of EosFP that can withstand these conditions...
  15. CRISPR 101: Multiplex Expression of gRNAs

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    Blog Post
    ...illustrated in the schematic below.   Figure 2: gRNA target sequences (colored rectangles) are cloned... plasmids: This plasmid set allows you to express 2-4 gRNAs, with four being the ideal number. First you...the total number of gRNAs you wish to clone, from 2-7. For example, if you’re expressing 4 gRNAs, you’...gRNAs into spectinomycin-resistant plasmids pX330S-2 to pX330S-(last gRNA number). The 5’ most gRNA is ...Multiplexing Plasmids: These plasmids allow you to assemble 2-4 gRNAs through Golden Gate or Gibson Assembly. gRNAs...Multiplex Plasmids: These plasmids allow expression of 2-5 gRNAs in zebrafish. Custom destination vectors are...and a subsequent curing protocol that requires only 2-3 hours incubation. Kondo Lab multiplexed base editing...
  16. Antibodies 101: Designing Your First Flow Panel

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    .... To understand why that is, let's look at Figure 2. The blue laser excites at a wavelength of 488 nm ... of PE's excitation spectrum (dotted line, Figure 2). The yellow/green laser, however, excites at 561 ... stronger — or brighter — signal.   Figure 2: Excitation and emission spectra for PE. The excitation...this example, I will describe a basic panel (Table 2, Figure 5) for a hypothetical experiment in the lab...efficiency (eGFP expression).     The first item in Table 2 is a standard and should always be included—the live...from the other fluorophores to avoid bleeding and 2) BV421 is a very bright fluorophore, which makes it...case the CD45 expression turns out to be weak. Table 2: A simple flow panel to detect live, transduced, and...
  17. Zhang Lab's CRISPR Frequently Asked Questions

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    Collection
    ...extraction solution, runs the protocol, then uses around 2-4ul in each 50ul PCR reaction. The gDNA extracted ... similar to using a single chimeric gRNA. At the same time, the off-target effects are reduced because...genomic PCR, but couldn't amplify the EMX1 gene using same primer you used in the Science paper ( Cong et al...
  18. 3 Tips to Improve HDR Efficiency for CRISPR Editing in Human Cells

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    Blog Post
    ...improving editing accuracy by preventing re-editing and (2) optimizing “cut-to-mutation distance”. Furthermore...also takes into account that HDR is rare, usually 2-5% of the edited cells in our hands, these combined...screen a few hundred clones to find the right one Step 2 – Edit the cells a second time using a repair template...Additional CRISPR Resources on Addgene's CRISPR Guide Page 2. Optimizing "cut-to-mutation distance"  Even though... wisely (and let them cut close).   Figure 2: Relationship between cut site to mutation distance...PMID: 23287718. PubMed Central PMCID: PMC3795411. 2. Mali, Prashant, et al. "RNA-guided human genome engineering... events were corrupted by unwanted indels on the same allele, probably due to concomitant NHEJ repair....
  19. CRISPR Between the Genes: How to Experiment with Enhancers and Epigenomics

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    ...for the 2+ million DHS sites. See below for further details. DNA is a 3D Fractal Figure 2: DNA compaction...: 1. Find Enhancers that have NANOG binding sites 2. Design a CRISPR screen to target and disrupt the ...NANOG enhancers 3. CRISPR out the enhancers from step 2. See which ESCs die or differentiate Step 3 reveals...expression for NANOG enhancers, we’re ready for step 2: design a CRISPR screen to disrupt these enhancers...to CRISPR out the enhancers we identified in step 2. The result is a heterogenous population of stem cells...lentiviral vector, an attenuated retrovirus in the same family as HIV. By design, our lentivirii are genetically...very-sensitive-local -L 9 -N 1 -U GRNA_23MERS -S GRNA_HITS.sam Many thanks to our guest blogger, Aneesh Karve...
  20. Plasmids 101: Knockout/Knock-In Plasmids

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    Blog Post
    ...the addition of Cre recombinase (Figure 2). Figure 2: A knockout targeting vector designed to... through an experiment designed to knock out exon 2 of a given gene.   Figure 1: A knockout targeting...For recombination to occur in a cell, a minimum of 2 kb of sequence homology is required, but 6 to 14 kb...construct to your target cells. After recombination, exon 2 of the targeted gene will be removed from the chromosome...the GFP/NeoR cassette is inserted in place of exon 2. Thus, the targeted gene is disrupted (knocked out...recombination event will remove NeoR only and leave exon 2 floxed, as seen in line 4 of Figure 4. Since the loxP...one of its exons has simply been replaced with the same sequence flanked by LoxP sites while the resistance...
  21. Plasmids 101: How to Verify Your Plasmid Using a Restriction Digest Analysis

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    .... Diagnostic restriction digests are comprised of 2 separate steps: 1) incubating your DNA with restriction...which cleave the DNA molecules at specific sites and 2) running the reaction on an agarose gel to determine...including a 1.2 kb insert. The plasmid was digested with 2 unique enzymes (HindIII and BamHI) and run on an agarose...to serve as a reference band. The uncut DNA (lane 2) shows 3 possible plasmid conformations, with relaxed... The glycerol in the buffer will make sure your sample settles in the gel well and the dyes provide a ...you to interpret the bands that you get in your sample lanes. Choose your ladder based on the expected...approximate the DNA mass of comparably intense samples of similar size. Run the gel at 80-150V until you...
  22. Optogenetics Guide

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    Guide
    ...influx into the cell when stimulated. Channelrhodopsin-2 (ChR2), the first widely adopted optogenetic tool,... (Phy) interaction 660 Cryptochromes Cryptochrome 2 and CIB1 Blue-light–mediated induction of protein ...interactions based on Arabidopsis thaliana cryptochrome 2 and CIB1 450 LARIAT Inhibits protein function by reversibly...customizable TALE DNA-binding domain with cryptochrome 2 protein and its interacting partner CIB1 to control...transcription effectors OPTOSTIM PHR domain2 of cryptochrome 2 (Cry2) from Arabidopsis thaliana is fused to truncated... with single-spike temporal resolution. PLoS One. 2(3):e299. PMID 17375185 Kim B, Lin MZ. 2013. Optobiology...comparative analysis of microbial opsins. Nat Methods. 9(2):159-72. PMID 22179551 Saunders A, Johnson CA, Sabatini...
  23. Fluorescent Proteins 101: Visualizing Subcellular Structures & Organelles

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    ... to the lysosome where they are finally degraded (2, 3). Once you've created your fusion protein, it's...examples include the ImageJ plugins JACoP and Coloc 2, BioImageXD, and customized CellProfiler pipelines...colocalization analysis example is given in Figure 2 (adapted from 4) - Dunn et al. 2011 provides an in-depth...Since colocalization relies upon the detection of 2 independent fluorescent signals and their potential...here! References 1. Allen Institute Plasmid Pages 2. Cooper GM. 2000. The Cell: A Molecular Approach. ...The same way the human body is made up of organs, cells comprise compartments and structures, called ...insights about the proximity of two proteins within the same subcellular structure or protein complex. By coexpressing...
  24. Adeno-associated virus (AAV) Guide

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    Guide
    ...indicates a virus containing the genome of serotype 2 packaged in the capsid from serotype 5. Use of these...neurons that are not efficiently transduced by AAV2/2, and is distributed more widely in the brain, indicating... pseudotyped with viral capsids from serotypes 1, 2, and 5 display differential efficiency and cell tropism...PJ, Mandel RJ, Muzyczka N. Mol. Ther. 2004 Aug;10(2):302-17. PubMed . From virus evolution to vector revolution...toolkit for human gene therapy. Wu Z, Asokan A, Samulski RJ. Mol. Ther. 2006 Sep;14(3):316-27. Epub 2006...independently of DNA synthesis. McCarty DM, Monahan PE, Samulski RJ. Gene Ther. 2001 Aug;8(16):1248-54. PubMed ...
  25. Rosella: A Fluorescent pH-Biosensor for Studying Autophagy

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    ...Table 2 for more details on the effect of pH on the fluorescent properties of Rosella.   Table 2: Effect...in yeast. Autophagy,4(2), 205-213. doi:10.4161/auto.5331. PubMed PMID: 18094608 2. Sargsyan, A., Cai, J...environment like the vacuole or lysosome. See Table 2 for a summary of what color fluorescence Rosella emits...fluorescence accumulates in the vacuole. See Figure 2 for an example of what fluorescence looks like for... practice to compare degradation rates between samples treated with or without an autophagy inhibitor....
  26. Tips for a 1st Time CRISPR User (by a 1st Time CRISPR User)

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    ...transductions and use a range of reasonable MOIs. 2. Create a monoclonal Cas9-expression cell line. Especially...doing a screen. I made a few monoclonal lines (Figure 2) and I was surprised at how variable Cas9-expression...across the different cells (Figure 3).   Figure 2: Cas9 expression in monoclonal cell lines generated... expression Overview: By Western blotting (Figure 2, pool), I knew the cells expressed Cas9, but I didn... appear green despite having active Cas9 (see tip 2). Pro-Tips 1. To quantify Cas9 activity using this...Western blotting against GFP expression, but I didn’t. 2. In the original publication they see GFP expression...and I got clear bands using the conditions above. 2. Design your primers so that the digestion site isn...
  27. Technical Design of a Western Blot

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    .... The most common options are 4 °C overnight or 1–2 hours at room temperature (RT). Most people choose...overnight at 4 °C and their secondary antibody for 1–2 hrs at room temperature, which allows them to reduce...Tris-glycine 6–400 kDa Tris-glycine 100 V, 1–2 hours Easy and cheap to handcast Short shelf-life...–40 kDa Tris-tricine 30 V, 1 hour or 100 V, 1–2 hours Good separation, quality, and stability ...separation of proteins of different sizes.  Table 2: Recommended gel percentages for various protein sizes...are consistent and stable at room temperature for 1–2 years and are available in formulas specific to your...response over a broad dynamic range that typically spans 2–5 orders of magnitude, which includes a wide dynamic...
  28. The Materials Science of Optogenetics Experiments

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    ...different steps and materials required for each [1, 2]. This protocol [3] provides, in exquisite detail,...stimulation         In the video above, Channelrhodopsin 2 (Chr2) has been expressed in the motor cortex of a...lasers are relatively cheap and will run you about $2-3,000/laser. However, an important caveat is that ... the light-gated cation channel, Channelrhodopsin 2 (ChR2), exists in several states: closed/light receptive...PMID: 21628464; PubMed Central PMCID: PMC3138296. 2. Sparta DR, et al. Construction of implantable optical...board, Jacqueline N Crawley  [et al]. 2012;Chapter 2:Unit2 16. doi: 10.1002/0471142301.ns0216s58. PubMed...be at least 85% of the initial laser output. The same considerations apply to the polishing and preparation...
  29. CRISPR-based Genome Editing Systems For Editing in E. coli

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    ...plasmids are cured from the cell. Steps 1-1 and 1-2 can be done simultaneously. Image from Li et al., ...1) replaced the promoter of gRNA-pMB1 with PrhaB, 2) changed the replicon of pCas into a non-temperature-sensitive... pEcCas/pEcgRNA system in 4 E. coli K-12 strains, 2 E. coli B strains, 1 E. coli W strain, and 1 Tatumella...MUCICAT better, it is faster. Using MUCICAT only needs 2 newly constructed plasmids (pDonor and pQCascade) ...rounds of transformation in 30 days. Figure 2: (A) MUCICAT plasmids for multicopy integration. (...our metabolic engineering case study of N-acetylglucosamine biosynthesis, we constructed a strain library...rounds of transformation to complete the N-acetylglucosamine strain library construction in 8 days. To ...
  30. Viral Vectors 101: AAV Variables That Matter

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    ...testing your AAV.  Figure 2: Comparison of AAV serotypes 1, 2, 5, 6, 8, and 9 in two different ...) your experimental conditions and measurements; (2) the cells you’re targeting; (3) how much expression... Tropism and Axonal Transport of AAV Serotypes 1, 2, 5, 6, 8 and 9 in the Mouse Brain. PLOS ONE, 8(9),... Comparison of four promoters. Gene Therapy, 28(1–2), 56–74. https://doi.org/10.1038/s41434-020-0169-1...analyses of adeno-associated viral vector serotypes 1, 2, 5, 8 and 9 in marmoset, mouse and macaque cerebral... different phenotypes of the same cell type, are intermingled in the same brain nucleus: a serotype that...tropism between animal species or even strains of the same species. What works well in a mouse may not work...
  31. Starter guide to induced pluripotent stem cells (iPSCs) part 1:  A renaissance in regenerative medicine

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    ...them in Regenerative Medicine. Acta Naturae, 2010. 2(2): p. 18-28. PubMed PMID: 22649638. PubMed Central...detail below [2]. Multipotency: When a cell can differentiate into multiple cell types of the same lineage....capability to differentiate into specialized cell types [2]. We general speak of 4 levels of stem cell potency...zygote through to the morula stage are totipotent [2-4]. Pluripotency: When a cell has the ability to differentiate...PMID: 26726264. PubMed Central PMCID: PMC4686367. 2. Jaenisch, R. and R. Young, Stem cells, the molecular...
  32. MXS Chaining

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    ...modules (Figure 2) are contained in individual plasmids and are each flanked by the same multiple cloning... TagBFP 399nm/ 456nm histone 2B (H2B) Chromatin 2 Cerulean 433nm/ 475nm Lyn-tag (derived from the tyrosine-protein...between various cloning methods are listed in Table 2. For example,  chaining-based cloning methods require...suitable for combining endogenous sequences. Table 2: High Throughput Cloning Strategies Method Technology...PMID: 20205762. PubMed Central PMCID: PMC2822740. 2. Engler C, Kandzia R, Marillonnet S. A one pot, one...e.g., a set of various mammalian promoters), the same cloning procedure can be used to incorporate each...
  33. Using AAV for Neuronal Tracing

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    .... Neuron 84(2), 292–309. PubMed PMID: 25374356. PubMed Central PMCID: PMC4269290. Masamizu, Y., Okada,...for retrograde transport has been found for AAV1, -2, -5, -7, -8 (Taymans et al., 2007), AAV1 (Hollis et... tropism and axonal transport of AAV serotypes 1, 2, 5, 6, 8 and 9 in the mouse brain. PLoS One 8:e76310...reveal novel hippocampal CA2 circuits. Nat Neurosci 17(2), 269–279. PubMed PMID: 24336151. PubMed Central PMCID...transduction efficiency of recombinant AAV serotypes 1, 2, 5 and 8 in the rat nigrostriatal system. J Neurochem...analysis of adeno-associated viral vector serotypes 1, 2, 5, 7 and 8 in mouse brain. Hum Gene Ther 18, 195–...retrograde access to projection neurons. Neuron 92(2), 372–382. PubMed PMID: 27720486. PubMed Central PMCID...
  34. Deep Dive: Statistical Tests (Comparisons)

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    ...typically, normal (bell curve) or skewed (see Fig. 2). Assumptions – characteristics of a data set; ...levels of variance among data.     Fig. 2: Examples of data distribution profiles.   Parametric... positive is much higher than if you only look at 2 or 3 pairwise comparisons. Similar to family-wise ...statistical facets of reproducibility. Adv Physiol Educ. 40(2): 248-252 (2016). 0.1152/advan.00042.2016 Finch, W...Simulation Study. Front. Appl. Math. Stat. Volume 2 (2016). doi.org/10.3389/fams.2016.00002  ...comparisons. Paired and unpaired t-tests Samples that come from the same subject or population - before and ...referred to as two-sample or independent, but these designations all refer to the same test. On some occasions...
  35. Multiplexed Capture of Promoter-enhancer 3D Chromatin Structures Using CRISPR

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    ...dCas9 and an eGFP tag, and 2) gRNAs Number of loci targeted One Many Sample type(s) Cell lines Cell ...Originally published Dec 7, 2017 and updated Jul 2, 2020. Promoters may be the star of gene regulation...sequence targeted in the experiment. Figure 2: Comparing CAPTURE and CAPTURE 2.0.     Original...cell line expressing 1) FLAG-biotin-tagged dCas9, 2) BirA, and 3) one or more gRNAs Two separate lentiviruses...identified and the level of on-target enrichment. 2. Determining the spatial and hierarchical organization...Cytogenetics, 11. https://doi.org/10.1186/s13039-018-0368-2  Liu X, Zhang Y, Chen Y, Li M, Zhou F, Li K, Cao H...
  36. Golden Gate Assembly Upgrades: More Fragments, Faster Assembly, and Higher Fidelity

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    ...Golden Gate Assembly is commonly used to assemble 2–10 DNA fragments in a single “one-pot” reaction to...the transformants onto the selection plate. Figure 2 shows representative transformation plates obtained...fidelity studies conducted by Potapov et al. at NEB (1, 2). While T4 DNA Ligase, the mainstay of most biotechnological... (percent correct) Calculated colony totals Per 2 μl assembly reaction Per full assembly reaction** ...calculated yields from entire outgrowth built from 2 µl of the assembly reaction, and from the entire assembly...fidelity and bias profiling." bioRxiv (2018): 322297. 2. Potapov, Vladimir, et al. "A single-molecule sequencing...confirmed the insertion of the Lambda insert at the same high frequencies as the antibiotic selection markers...
  37. Minigenomes - a Safe Way to Study Dangerous Viruses Like the Ebola Virus

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    ...genome (Figure 2). While it is technically possible to encode all four viral genes in the same plasmid (as...study aspects of the EBOV replication cycle under BSL-2 conditions (4). What is a minigenome?   The EBOV ...transcription by the EBOV polymerase (reviewed in 2, 5). The minigenome is capable of being replicated...nonsegmented negative sense RNA viruses (reviewed in 2, 3). Other important components of the Zaire ebola...500 ng NP, 500 ng VP35, 100 ng VP30, 100 ng L, and 2 μg minigenome plasmid per well (in a 6 well plate ...PubMed PMID: 9847328. PubMed Central PMCID: PMC103829. 2. Conzelmann, K. K. "Reverse genetics of mononegavirales...
  38. Cpf1: A New Tool for CRISPR Genome Editing

    Type
    Blog Post
    ...Cpf1 is a single RNA-guided endonuclease of a class 2 CRISPR-Cas system. Figure from Zetsche et al., 2015...2015. How was Cpf1 found and tested? Class 2 CRISPR systems, including the type II Cas9-based system...employed by class 1 systems. A putative new class 2 nuclease, Cpf1 (CRISPR from Prevotella and Francisella... the 3’ end of the target sequence. Figure 2: Effects of (A) double and (B) single base pair gRNA-target...Cpf1 is a single RNA-guided endonuclease of a class 2 CRISPR-Cas system." Cell (2015). PubMed PMID: 26422227... Find plasmids from this publication at Addgene. 2. Zetsche, Bernd, et al. "Multiplex Gene Editing by...cleavage are 42-44 nucleotides in length, about the same size as Cas9’s, but with the direct repeat preceding...
  39. Antibodies 101: Chimeric Antibodies

    Type
    Blog Post
    ...use 2 different secondaries for your antibody pair and visualize both targets in parallel (Fig. 2). For...both proteins.     Figure 2: Two primary antibodies with the same isotype can not be used for multiplexed... are the same isotype and therefore cannot be indirectly probed simultaneously on the sample. What to ...because the pair belong to the same isotype and will react with the same secondary. If you were to change...that group. If you use two antibodies that are the same isotype then the secondary antibody will bind to...
  40. Antibodies 101: ChIP

    Type
    Blog Post
    ...to (1) run a DNA gel to confirm fragment size and (2)  incubate with RNAse and Proteinase K to purify the...proteins of interest to any DNA they were bound to (2) fragmented the DNA (3) used antibodies to specifically...adjustments, to get everything just right!  Fig. 2: Goldilocks is actually celebrating a successful ChIP...you’re working with a tissue sample, you’ll need to homogenize your sample before moving on to the next...Homogenization for a tissue sample can also need significant optimization for the sample type and size.) It can...process is very similar for both, though tissue samples do require an extra homogenization step. For this...to focus on the ChIP process and not the upsteam sample collection process or the downstream analysis process...
  41. Mouse Modeling, Part 2: Breeding and Crossing Mice

    Type
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    ...detect your targeting vector or gene of interest. 2. Breed your parental mice to generate F1 Once you’...experimental and control mice will have been raised in the same environment and will harbor similar epigenetic modifications...multiple mutations is if the mutations are on the same chromosome. Homologous chromosomes recombine during...two loci, which would get both mutations onto the same chromosome. Until crossing over occurs between the...
  42. Plasmids 101: Restriction Cloning

    Type
    Blog Post
    ...backbone alone; 2. Transformation containing ligation mixture with insert and backbone. Sample results indicative... used. Follow the manufacturer’s instructions.   2. Isolate Your Insert and Vector by Gel Purification...DNA concentration alone. One method is to conduct 2 ligations for each plasmid you are trying to create...colonies than the vector + insert plate (unsuccessful 2), or roughly equivalent numbers of colonies on each... or equivalent to backbone + insert, unsuccessful 2 and 3 above), you can try ligating the recipient plasmid...between samples. In addition to a DNA ladder standard, it is also a good idea to run an uncut sample of each...you to either stain your gel after you run your samples or add the stain as the gel is being made (post...
  43. 22 Hot Plasmid Technologies from 2014

    Type
    Blog Post
    ...Currently available from the Kim lab are 2 presynaptic and 2 postsynaptic targeting mGRASP plasmids. Additionally... cells were pulsed with 2µg/ml of Doxycycline for 2 hours, and imaged on the Keyence BZ-9000 fluorescence...work! Robinson et al., Dev Cell 2010 Feb 16;18(2):324-31. Cheeseman et al., J Cell Sci 2013 May 1...promotes the formation of an isopeptide bond between 2 peptide tags, SpyTag and KTag. The group demonstrated... of three sets of cloning vectors (Level 0, 1, or 2) which can be utilized in three successive assembly...1 modules can be similarly assembled into a Level 2 vector, thus forming a functional genetic circuit....circuit. Flexibility has been built into the Level 2 vectors to allow for additional iterations of Level 1 assembly...
  44. CRISPRainbow and Genome Visualization

    Type
    Blog Post
    ...two genes over time, at a range of distances from 2-75 Mbp. Labeling multiple, intrachromosomal loci Building...successfully resolved loci with physical map distances of 2 and 75 Mbp, with the calculated fluorescent distances...established physical map. In comparing pairs of targets ~2 Mbp apart, they noticed that they could evaluate the...dCas9 supplied by a separate vector. Figure 2: CRISPRainbow generates 6 unique colors and a white... Find plasmids from this publication at Addgene. 2. Ma, Hanhui, et al. “Multicolor CRISPR labeling of...plasmids from this publication at Addgene. 4. Kiani, Samira, et al. “Cas9 gRNA engineering for genome editing...
  45. Tetbow: Bright Multicolor Labeling for Neuronal Tracing

    Type
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    ...possible when each of the XFP genes is introduced at ~2 copies per cell per color, following a Poisson distribution...(prepared with Addgene #104110 - #104112) (Figure 2). We’ve also created constructs with containing chemical...AAV titer - The XFP genes have to be introduced at ~2 copies per cell per color to achieve the highest color...not powerful enough for large brain samples. For large brain samples, we recommend pretreatment with ScaleCUBIC1...time points, sacrifice the animals and fix the samples. When you use AAVs, it typically takes a few weeks...excessive amount of XFPs expressed. Then, clear the samples and visualize. For more details on this procedure..."Optical clearing and index matching of tissue samples for High-resolution fluorescence imaging using ...
  46. Addgene is Expanding Our Viral Vector Service!

    Type
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    ...Request review: 1–2 days Prep and QC completed: 6–8 weeks Average shipping time: 1–2 days (USA); 3–4 days... our production process. This process will take 1–2 days, and we anticipate approving the vast majority...produce your Packaged on Request prep and run the same quality control assays we run with all of our in-stock... be 1x1013 and titers for AAV2 to be 7x1012, the same titers found in our in-stock preps. If a request...
  47. Viral Vectors 101: An Introduction to AAV

    Type
    Blog Post
    ..., AAV2/8 has a type 2 ITR and a type 8 serotype. Almost all vectors contain type 2 ITRs, which comes from...differentiated, non-dividing cells.   Figure 2: DNA rescue and transduction of a conventional single-stranded...quantitative PCR-based method for the titration of AAV-2 vector stocks."Molecular Therapy 6.2 (2002): 272. ...episomal and does not divide and replicate in the same way the host DNA does. Because of this, fast dividing...McCarty, D. M., Paul E. Monahan, and Richard J. Samulski. "Self-complementary recombinant adeno-associated...
  48. Plasmids 101: FLEx Vectors

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    ...conditional knock-in cassette. As shown in Figure 2, the cassette should contain a reporter DNA sequence...a targeted neuronal population.    Figure 2 (modified from Schnutgen et al. Nat Biotech 2003):...cellular level in the mouse. 2003 PubMed PMID: 12665802. 2. Branda, CS and Dymecki, SM. Talking about a Revolution... SM. 2008. A FLEX switch targets Channelrhodopsin-2 to multiple cell types for imaging and long-range ...between the sites. If a DNA sequence is floxed in the same orientation, the SSR will excise the DNA fragment...reporter with one loxP site and one lox511 site in the same orientation, and placing the additional loxP and...
  49. Viral Production at Addgene

    Type
    Blog Post
    ...digital PCR. Human Gene Therapy Methods, 25(2), Article 2. https://doi.org/10.1089/hgtb.2013.131 Wang,...(see maps section for images).     Figure 2: AAV Pro cells were transduced with either pAAV-Ef1a-mCherry-IRES-Cre...Digital PCR Method. Human Gene Therapy Methods, 29(2), 96–103. https://doi.org/10.1089/hgtb.2017.198   ...of the viral capsid proteins VP1, VP2, and VP3. Samples of viral preparations are subjected to polyacrylamide...proteins as a fraction of total protein present in the sample is also determined and used to determine purity...shown relative to the total protein present in the sample.   Sterility Viral vector preparations are ...rigorous barcode matching system that follows the sample from the DNA tube all the way to the cleared viral...
  50. A Needle in a Base-Stack: Cas9 Structural Biology

    Type
    Blog Post
    ...those in Figures 2 and 3 don’t show these regions, even if they are present in the sample. Other techniques...Cas9 from Streptococcus pyogenes.   Figure 2:  Crystal structure of S. pyogenes Cas9 in the apo...NUC and REC lobes laying open like a book (Figure 2). The portion of the CTD that recognizes the PAM is...it doesn’t appear in the crystal structure (Figure 2) at all. When this crucial recognition region is disordered...itself at the bottom of the image. Stem loops 1 and 2 extend horizontally across both lobes. The guide RNA...is required for Cas9 nuclease function. Stem loops 2 and 3 are not strictly necessary for in vitro cleavage...open conformation, but highly flexible, as in Figure 2. The guide RNA is bound primarily by the REC lobe,...
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