We narrowed to 587 results for: cel.2
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TypeBlog Post...single RNA-guided endonuclease of a class 2 CRISPR-Cas system." Cell (2015). PubMed PMID: 26422227. Find ...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...Find plasmids from this publication at Addgene. 2. Zetsche, Bernd, et al. "Multiplex Gene Editing by CRISPR–Cpf1...orthologs that display cleavage activity in mammalian cells. Like Cas9 nucleases, Cpf1 family members contain...
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Important Considerations When Using AAVs
TypeBlog Post...University of Manitoba due to their Biosafety Level-2 or 2+. Please Note: Despite the fact that AAVs themselves...Location (1): What tissue? Location (2): Where in the tissue/which cell type? Location (3): Traveling from...in very specific cell populations. Find Ready-to-Use Retrograde AAV Preps at Addgene 2) Comparison of genetically...long and stable expression (up to 9 months in mice [2]). Low Immune Response: Compared to other viral vectors...may be sufficient to overcome the transport issues. 2. Failure to plan (for storage) Is planning to fail...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 (... -
Fluorescent Proteins 101: Photoactivatable Fluorescent Proteins
TypeBlog Post...fluorescent state make them useful for 2-color imaging with green PA-FPs. Table 2: Properties of Selected Reversible...PA-FPs come in 2 flavours- monomeric and tetrameric. Tetrameric PA-FPS are better for whole cell imaging and... of proteins and cells." Science 297.5588 (2002): 1873-1877. PubMed PMID:12228718. 2.Subach, Fedor V.,... 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... -
Screening for Successful Genome Editing with Digital PCR
TypeBlog Post... (details in [2]) and can be used to quantify rates of mutation in a bulk or single cell-derived genomic...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... successfully analyzed gDNA from a few thousand cells from single wells of a 96-well plate without prior... that they are easily able to distinguish single-cell derived samples with mono-allelic mutations versus... -
Finding nucleic acids with SHERLOCK and DETECTR
TypeBlog Post...Diverse Class 2 CRISPR-Cas Systems. Molecular Cell 60:385–397 . https://doi.org/10.1016/j.molcel.2015.10.008...Endonuclease of a Class 2 CRISPR-Cas System. Cell 163:759–771 . https://doi.org/10.1016/j.cell.2015.09.038 Additional... 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... a protocol for using SHERLOCK to detect SARS-CoV-2 RNA. The test is started using RNA purified from patient...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... -
Sleeping Beauty Awakens for Genome Engineering
TypeBlog Post... of 2 components: 1) an SB transposase, the enzyme required for catalysis of transposition; and 2) a transposon...stable transgenic cell lines. Biotechnol J. 2015 Feb 4. doi: 10.1002/biot.201400821. PubMed. 2. Mates L, et... gene (red) for expressing the transposase enzyme.2.) The transposase enzyme is expressed (red stars) ...to infect and replicate in host cells, but they are susceptible to cells’ defense mechanisms. The use of... transposon; the plasmid is then degraded by the cell.4.) The transposase creates a double strand break...improve its gene insertion efficiency in primary cells. In 2009, Zsuzsanna Izsvak’s lab screened many SB...tranposase variants for hyperactivity in mammalian cells. Their efforts resulted in a new and improved SB... -
CRISPRainbow and Genome Visualization
TypeBlog Post...Addgene. 2. Ma, Hanhui, et al. “Multicolor CRISPR labeling of chromosomal loci in human cells.” Proc. ...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...Genomic Loci in Living Human Cells by an Optimized CRISPR/Cas System.” Cell 155 (2013): 1379-1491. Pubmed...of 6 chromosome-specific loci in the U20S cancer cell line./ Each color represents a gRNA targeting a ... -
Plasmids 101: Modular Cloning
TypeBlog Post...TUs. Level 2: Assembly of multiple Level 1 TUs into multigene constructs. Figure 2: The three ...can be queried by testing any number in the Level 2 assembly. These pathways can require a lot of optimization... of multigene constructs. PLoS One. 2011 Feb 18;6(2):e16765. doi: 10.1371/journal.pone.0016765. Hahn,... (2020). https://doi.org/10.1186/s12870-020-02388-2 Resources on Addgene.org Addgene’s Modular Cloning...complex cellular behaviors requires making complex manipulations to cells. For example: in a cell there ... yield a cellular phenotype, translational output, etc., which can support a larger cellular engineering...TU, or even an individual part, will behave in a cell. For unpredictable cases, MoClo provides two answers... -
CRISPR 101: Multiplex Expression of gRNAs
TypeBlog 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... -
Multiplex Genome Editing with CRISPR-Cpf1
TypeBlog Post...expression and needing to work with a transfectable cell line. 2) They require larger expression vectors which...Single RNA-Guided Endonuclease of a Class 2 CRISPR-Cas System. Cell,163(3), 759-771. PubMed PMID: 26422227...are also larger than their Cpf1 counterparts. Table 2. Cas9 Multiplexing Options Multiplexing Method... Cpf1 expression vector. See the graph in figure 2 for a comparison of editing frequency resulting from...Biotechnology 35.1 (2016): 31-34. Pubmed PMID: 27918548. 2. Zetsche, B., Gootenberg, J., Abudayyeh, O., Slaymaker... of 4 crRNAs in vitro and when expressed in 293 cells. This allows for a single promoter to drive expression... were used. With transfection, 6.4% of HEK293T cells had edits at 4 of 4 targets when an array of 4 crRNAs... -
Antibodies 101: Designing Your First Flow Panel
TypeBlog Post...Table 2, Figure 5) for a hypothetical experiment in the lab. Let's say I am culturing HEK 293T cells in ... weak. Table 2: A simple flow panel to detect live, transduced, and CD45-expressing cells. Marker .... 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...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... -
Genome-wide Screening Using CRISPR
TypeBlog Post...plasmid, or a 2-plasmid system in which Cas9 must be delivered separately. Mutant cells are enriched ...diseases causing uncontrolled cell growth, such as cancer. Figure 2: The CRISPR library must be ...targeting a specific gene within the genome (see Fig. 2). Individual gRNAs are designed in silico using publicly...mouse, human, fly, E. coli, and T. gondii genes. 2) What genetic modification are you trying to make?...CRISPR libraries is a multi-step process (see Fig. 2). In most cases, CRISPR libraries are provided at ...heterogeneous population of mutant cells, with each cell or set of cells containing a mutation in a different...fluorescence-based cell sorting and screened for a particular phenotype. For example, mutant cells can be used... -
A Primer on Optogenetics: Introduction and Opsin Delivery
TypeBlog Post...: PMC3337962. 8. Zhao S, et al. Cell type-specific channelrhodopsin-2 transgenic mice for optogenetic ...commonly used in optogenetics: 1) electrophysiology and 2) behavioral experiments. I’m not an electrophysiologist...choice in the brain region you wish to stimulate 2) Fabrication and implantation of the optical fiber...thoroughly elsewhere (here and here for instance) [2], [3]. Karl Deisseroth of Stanford University , one...reviews for a discussion of the different variants [1, 2, 4]. And, of course, the best way to learn about the...monitor expression at various time points (e.g. every 1-2 weeks over 8 weeks) in order to determine the optimal...(4):251-66. doi: 10.1038/nrn3171. PMID: 22430017. 2. Fenno L, et al. The development and application of... -
Luciferase Plasmid Collection
TypeCollection...and Venus fluorophore to Troponin C Ca 2+ binding domain. Nano-lanterns , Enhanced Nano-lanterns , and...transfection Feng Zhang 21471 pLenti PGK V5-LUC Neo (w623-2) Firefly PGK Lentiviral expression of firefly luciferase...Expression of firefly luciferase from a cell-free mammalian cell lysate Marcel Bruchez 108542 pLenti-EF1a-Luciferase-IRES-Blast-WPRE...not secreted, so cells must be lysed or the substrate must be delivered intracellularly in order to measure... viral infection efficiency, to study changes in cell physiology, or as a reference level of expression...interactions , protein dimerization , endosomal escape of cell-penetrating peptides , and more. nLuc/cLuc for split...Resonance Energy Transfer (BRET) CalFlux VNT : An intracellular calcium sensor created by fusing NanoLuc® and... -
Brain Initiative Collection
TypeCollection...Gordon Fishell 83899-AAV1 pAAV-mDlx-GCaMP6f-Fishell-2 GCaMP6f expression in forebrain GABA-ergic interneurons...Gordon Fishell 83899-AAV9 pAAV-mDlx-GCaMP6f-Fishell-2 GCaMP6f expression in forebrain GABA-ergic interneurons...Gordon Fishell 83899-AAVrg pAAV-mDlx-GCaMP6f-Fishell-2 GCaMP6f expression in forebrain GABA-ergic interneurons...real-time interrogation and monitoring of brain cells and circuits during behavior. Long desired by researchers...A somatic channelrhodopsin, which enables single cell, single millisecond resolution optogenetics. Human...A somatic channelrhodopsin, which enables single cell, single millisecond resolution optogenetics. Cre-dependent...genetically encoded dopamine sensor RdLight1 in mammalian cells. Lin Tian 125708-AAV9 pAAV-hSynapsin1-RdLight1 Expresses... -
Five Popular Model Organisms, Part 2
TypeBlog Post... H. J. (2009). Rats! Disease Models & Mechanisms, 2(5–6), 206–210. https://doi.org/10.1242/dmm.002733 ...are often used to study vertebrate embryology and cell development. One major resource for frog research...Organism to Study and Model Human Genetic Disease. Cells Tissues Organs, 205(5–6), 303–313. https://doi.org... -
Viral Vectors 101: Optogenetic Tools
TypeBlog Post...Optogenetic control of intracellular signaling pathways. Trends in Biotechnology, 33(2), 92–100. https://doi.org...for controlling neuronal activity, channelrhodopsin-2 (ChR2), a blue light-activated cation channel, from...used in tandem with the opsin. Figure 2: Diagram of excitatory (ChR2) activation by light ...) domains, phytochrome B (PhyB), and cryptochrome 2 (CRY2) (Zhang & Cui, 2015). When stimulated with light...comparative analysis of microbial opsins. Nature Methods, 9(2), 159–172. https://doi.org/10.1038/nmeth.1808 References...comparative analysis of microbial opsins. Nature Methods, 9(2), 159–172. https://doi.org/10.1038/nmeth.1808 Nagel...Hegemann, P., & Bamberg, E. (2003). Channelrhodopsin-2, a directly light-gated cation-selective membrane ... -
Plasmids 101: Dimers and Multimers
TypeBlog Post...identification. Fig. 2: Gel image of Plasmid 61564: pBAMD1-2 (~4.7 kb) digested with SpeI and...to the formation of plasmid multimers. Cell. 1976 Dec;9(4 PT 2):707-16. doi: 10.1016/0092-8674(76)90134... 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...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...at lower copy numbers within bacterial cells, and bacterial cells with multimers grow more slowly compared... -
Flow Cytometry Readouts: Yes, No, and Everything in Between
TypeBlog Post...low expression, and everything in between (Figure 2). These smears tend to occur when you are looking ...on your experiment. You can see from Figure 2 that determining where to place your gate based on the dot... dot plot would be complicated. Figure 2: (A) a smeary dot plot showing a range of antibody readouts...plot in Figure 4 compared to the dot plot in Figure 2. Quantification using MFI makes it easier to identify...percentage of total live cells are GFP+. In this plot, with adjusted voltage, cells that did not receive ...would serve you well. Percentage of cells in a parent gate (all live cells for example) that are positive ...example, you have introduced a GFP protein into your cells (visualized via the FITC channel) and you are trying... -
CRISPR 101: Targeting RNA with Cas13a (C2c2)
TypeBlog Post...question: C2c1, C2c2 and C2c3 (short for Class 2, candidate 1, 2, or 3). C2c1 and C2c3 are related to Cpf1,...characterization of diverse class 2 CRISPR-Cas systems." Molecular cell 60.3 (2015): 385-397. PubMed PMID...however cutting efficiency of Cas13a is reduced when 2 mismatches are present. The protospacer flanking sequence...PMC5127784. Find plasmids from this paper at Addgene. 2. East-Seletsky, Alexandra, et al. "Two distinct RNase...thought to activate programmed cell death or a dormant state for bacterial cells that have been infected with...bacterial cells, LwaCas13a does not display nonspecific RNA cleavage activity in eukaryotic cells. They arrived...target RNAs, although its usefulness in bacterial cells will likely be limited by the propensity of Cas13a...