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We narrowed to 604 results for: abo.2

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  1. Antibodies 101: Normalization and Loading Controls for Western Blots

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    Blog Post
    ...condition 1” than “condition 2.” By eye, the loading control appears about the same between the two conditions...the resulting fraction is reported. Figure 2: Normalization with loading controls. Under each lane...control band is weaker in condition 1 than condition 2, the normalized values for the two conditions are ...opposite change in your loading control. Assumption #2: The loading control can be accurately quantified ...) are smaller than the analogous green “condition 2” points by the exact same value. For the two solid...consider a different loading control. Assumption #2: The loading control can be accurately quantified ...factors we’ve covered in our previous blog posts (1, 2) on western blotting. If the abundance of your POI...
  2. Antibodies 101: Fab Fragments

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    Blog Post
    ...fragments that retain antigen binding (Figure 2):  F(ab')2 - These fragments are produced by proteolytic...fragments are produced by mild reduction of F(ab')2 fragments, which reduces the hinge region disulfide...Variable (scFv). Size: ~25 kDa.   Figure 2: Comparison between a full IgG antibody and common...advantages, though with some caveats.  First off, F(ab’)2 fragments are bivalent, so may have higher avidity...or Fab fragments. Higher avidity means that F(ab’)2 fragments may have overall stronger interaction with...Clinical Prospects of Antibody Fragments. Antibodies 8(2):28. https://doi.org/10.3390/antib8020028    Wessel...multiplexed super-resolution microscopy. Cell Rep Methods 2(10):100301. https://doi.org/10.1016/j.crmeth.2022.100301...
  3. Addgene's Top Blog Posts from 2020

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    Blog Post
    ...CRISPR to detect SARS-CoV-2, including many with plasmids deposited at Addgene! 2. DNA Purification Without...detection methods, synthetic nanobodies, SARS-CoV-2 protein expression, and more. We also highlighted ...empty backbones, fluorescent protein tags, SARS-CoV-2 plasmids, etc. It is our hope that by providing cloning...RNA and extracting RNA without a kit. 3. SARS-CoV-2/COVID-19 Detection Methods Based on CRISPR/Cas by ...highlighted reagent repositories and other collaborative efforts in the scientific community to speed COVID-19 research...store my plasmid in TE, Tris, or water? And what about temperature? Find the details in this blog post....dominates DNA quantification discussions, but what about the other methods to quantify DNA? Here we cover...
  4. 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...completely inert, but others can cause diseases. Nervous about handling viruses? That’s okay! In this article we...
  5. 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...
  6. Uncertainty about Labor Law Brings More Uncertainty to Postdoc Wages

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    Blog Post
    ...that increase cancelled. Rounding out the remainder, 2% of postdocs who weren’t going to get a salary increase...with their plans, and 17 have cancelled their plans. 2 of those raising - the University of Illinois and ...Previous Article: Changing Labor Laws Bring Increased Postdoc Wages Read about the Advocating for Science... of $47,476 per year, under updates to the Fair Labor Standards Act (FLSA). This was due to the threshold...postdocs - and in some cases, faculty - have found out about what their institution is doing from Future of Research...Science Symposium and Workshop Learn about a Variety of Science Careers Resources on Addgene.org Find Career...
  7. Giving gRNAs a Facelift - Synthetic and Beyond

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    Blog Post
    ...same site, is 2’-fluoro (2’-F), which substitutes a fluorine for the hydroxyl group at the 2’ position. ...most common of these is 2’-O-methylation, where a methyl group is added to the 2’ hydroxyl group of the...them together, for example phosphorothioates with 2’-O-methyl modifications, proved more stability than...generated by introduction of a single photocleavable 2-nitrobenzyl linker in the 20-bp targeting region of...“I hope it isn’t degraded” when scientists talk about their precious RNA samples. RNA is inherently less...efficacy as well as the unnecessary stress of worrying about the status of your RNA. gRNAs modifications are ...Some of the RNA stabilizing modifications listed above were developed before CRISPR-Cas9, for use in applications...
  8. Great Results Start with Great Standard Curves

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    Blog Post
    ... Figure 1 depicts a 2-fold dilution series. Each step of the series dilutes by 1:2 for a series that ranges...series ranging from 1:2 to 1:32. Each individual step of the series is consistent at 1:2. When preparing a.... An example of this is shown in Figure 2.   Figure 2: The concentration of a serially diluted... ranges from 1:2–1:32. The specific dilution series used will depend on the expected concentration of ...accuracy of the curve, avoid pipetting small volumes (< 2 µL) or volumes too large for a standard micropipette...by replicate values provides useful information about the accuracy of the curve, which we will discuss...many scientific applications users aim for an R2 above 0.95.    Additional considerations When running ...
  9. Lambda Red: A Homologous Recombination-based Technique for Genetic Engineering

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    Blog Post
    ...generate 2 possible products: 1) a partially dsDNA duplex with single-stranded 3’ overhangs or 2) if the...recombineering system has three components (Figure 1): 1) Exo, 2) Beta, and 3) Gam. All three are required for recombineering...generic lambda red recombineering experiment (Figure 2). In the following sections, key steps that differ...confirmation of recombinant clones.    Figure 2: Overview of using Lambda Red recombineering system...pairs of homology to the targeted insert site (Figure 2, top).  These primers are typically ~70 nucleotides...bacteria that has key MMR proteins knocked out or 2) specially design ssDNA oligos to avoid MMR: 1) E....will have more unintended changes to their genomes. 2) Designing ssDNA oligos that avoid MMR activation:...
  10. Typing CRISPR Systems

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    Blog Post
    ...   Class 1 versus class 2 There are two CRISPR classes: Class 1 and Class 2. Class 1 CRISPR systems use...systems to carry out various functions. Class 2 Class 2 CRISPR systems rely on a single protein Cas effector...explore Class 2 CRISPR in more depth, the Jennifer Doudna lab maintains an encyclopedia of Class 2 CRISPR systems...systems: a burst of class 2 and derived variants. Nature Reviews Microbiology, 18(2), 67–83. https://doi.org...complex for antiviral defense) complexes, while Class 2 use single protein Cas effectors, like Cas9. The Cascade...1 remains largely underutilized compared to Class 2. Class 1 Despite their incredible abundance, Class...components present in the Cascade complex. Figure 2: Schematic of a Cascade complex (blue subunits) with...
  11. 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...inserted GFP is expressed (knocked in). As seen in the above example, you can remove a floxed resistance gene...
  12. Tips for a 1st Time CRISPR User (by a 1st Time CRISPR User)

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    Blog Post
    ...designed (listed above) worked well and I got clear bands using the conditions above. 2. Design your primers...expression, but I didn’t. 2. In the original publication they see GFP expression in about 20% of their Cas9-expressing...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...
  13. Plasmids 101: Secondary Nanobody Toolbox

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    Blog Post
    ...between a fluorescent tag and the target antigen to about 2 nm, which can lead to higher resolution for super-resolution...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° ...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., ...
  14. Rosella: A Fluorescent pH-Biosensor for Studying Autophagy

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    Blog Post
    ...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...information about the contents of the autophagosome nor does it provide information about what is being...higher pH of the vacuole. Read on to learn more about prior methods for studying autophagy and how Rosella... (as opposed to giving more fine-grained detail about what proteins or organelles are being degraded) ...
  15. Hot Plasmids - October 2022

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    Blog Post
    ...GEVIs (called ASAP 1 and 2), they found an indicator that is optimized for 2-photon imaging of voltages...resultant JEDI-2P sensors overcome many challenges in 2-photon in-vivo imaging of voltage fluctuations. Image...suitable for in vivo optogenetic use.   Fig. 2: A) HcKCR1 is highly selective for K+ over other Na...slice of HcKCR1-EYFP and tdTomato expressed layer 2/3 neurons in mouse. C) Action potential frequencies...Brian O'Neill  The François St-Pierre lab and collaborators have successfully developed an improved voltage...
  16. The Materials Science of Optogenetics Experiments

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    Blog Post
    ...Laser stimulation         In the video above, Channelrhodopsin 2 (Chr2) has been expressed in the motor...These lasers are relatively cheap and will run you about $2-3,000/laser. However, an important caveat is that...different steps and materials required for each [1, 2]. This protocol [3] provides, in exquisite detail,... 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...distance so ideal implant placement should be about 0.4-0.5mm above the site of your stimulation. The scatter...
  17. 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 ... cloning Read our Plasmids 101 blog posts Learn about the differences between transformation, transduction...
  18. Viral Vectors 101: Producing Your rAAV

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    Blog Post
    ...digital PCR. Human Gene Therapy Methods, 25(2), Article 2. https://doi.org/10.1089/hgtb.2013.131 Lock,... 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 ..., R., & Kleinschmidt, J. (1999). Titration of AAV-2 particles via a novel capsid ELISA: Packaging of genomes... 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...dehydration (Howard & Harvey, 2017). You can learn more about common AAV applications by reading our Viral Vectors...
  19. Deep Mutational Scanning with One Pot Saturation Mutagenesis

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    Blog Post
    ...image above). A second universal primer is used to synthesize a complementary mutant strand (step 2 and ... 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...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...
  20. CRISPR Between the Genes: How to Experiment with Enhancers and Epigenomics

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    Blog Post
    ...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...republished here with permission. Quilt is a collaborative database for genomics. In this article, Quilt...tri_methylation In the next section we’ll apply the above formula to a real-world experiment. We’ll start ...
Showing: 61 - 80 of 604 results