We narrowed to 587 results for: cel.2
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TypeBlog Post...guide expression and dsDNA breaks. Figure 2: Non-targeting vs. safe-targeting guides. The genome-wide...target all protein-coding genes present in the genome; 2) non-targeting guides (red), which target no sequence...guides that had zero mismatch off-targets. Guides with 2-bp mismatch off-targets were only toxic if they had...tolerated than mismatches more distal to the PAM, and 2) guides with high GC content have greater off-target...PMID: 28474669. Pubmed Central PMCID: PMC5424143. 2. Tsai, Shengdar Q., et al. "GUIDE-seq enables genome-wide...delivered as a pooled library via a lentiviral vector to cell lines that either stably expressed Cas9 or that ...almost all genes involved in the production of a cell surface glycan that’s required for ricin uptake....
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15 Hot Plasmids from 2017
TypeBlog Post...NGG) Editing window ~2 nt 85175 pBK-EE-BE3 SpCas9 (NGG) Editing window ~2 nt 85176 pBK-YE2-...quantum yield of 0.54) and mScarlet-H with M164H (2-fold improvement in photostability compared to mScarlet...SpCas9 base editors with editing windows as small as 1-2 nucleotides! To reduce off-target effects associated...pBK-YE2-BE3 SpCas9 (NGG) Editing window ~2 nt 85177 pBK-YEE-BE3 SpCas9 (NGG) Lower on-target activity...activity than BE3; editing window ~1-2 nt 87438 pET42b-HF-BE3 HF-Cas9 (NGG) Very low off-target activity...Ladders Are Awesome Tools: They are comprised of 2 plasmids, pPSU1 and pPSU2, that can be amplified affordably...libraries The Gross Lab at UCSF recently deposited 2 Bacillus subtilis libraries with Addgene – the B. ... -
Viral Vectors 101: Integrase-Deficient Lentiviral Vectors
TypeBlog Post...or non-homologous end joining (see Figure 2). Figure 2: Schematic representation of integration...developing T-cell acute lymphoblastic leukemia due to insertional mutagenesis (Howe et al., 2008). 2. Transient...vectors: progress and applications. Gene Therapy, 17(2), 150–157. https://doi.org/10.1038/gt.2009.135. PubMed...efficiently during infection. Journal of Virology, 70(2), 721–728. https://doi.org/10.1128/JVI.70.2.721-728.1996...purposes, like creating stable cell lines, delivering CRISPR/Cas9 to cells for genome editing, and introducing... chromosome of the cell. This integrated viral genome is then part of the cellular DNA… forever! This...viral entry into the host cell. Transfecting these three plasmids into cells enables the production of... -
Viral Vectors 101: What is a Virus (and a Viral Vector)?
TypeBlog Post...developed around how they replicate (Figure 2). Figure 2: Baltimore replication classes. Image credit...safer viral vectors that can be used in BSL-1 or BSL-2 labs. Viral vectors are viruses that have been genetically...hijacking the machinery of the cells they infect. Once they enter a cell, they treat their viral genome...genome as a “payload” that is delivered to the cell. The cell then uses its own machinery to replicate the...replication process whereby one cell copies itself and “splits” into two cells. Viral vectors Viruses are ...virus. From one, come many After a virion infects a cell, the single particle creates many copies of itself...millions of new copies, which are released from the cell like baby spiders from an egg sac. (Okay, some enveloped... -
Technical Design of a Western Blot
TypeBlog Post.... 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... -
Delivery Methods for Generating iPSCs
TypeBlog Post... and future challenges." Journal of Cellular Physiology 228, no. 2 (2012): 267-75. PubMed PMID: 22767332...Pluripotent Stem Cells, 2013, 23-33. PubMed PMID: 23546745. PubMed Central PMCID: 4176696. 2. Yusa, Kosuke...Gene-delivery systems for iPS cell generation. Expert opinion on biological therapy, 10 2, 231-42. PubMed PMID:...plasmid-based expression requires serial transfection of 1 or 2 plasmids that express the reprogramming factors of...for generating iPSCs by plasmid transfection where 2 of 11 clones tested had plasmid integration. Another...understanding the mechanisms of reprogramming, and 2) studies with clinical endpoints. In the first scenario...PubMed PMID: 27764162. PubMed Central PMCID: 5072705. 2. Sommer, Cesar A., and Gustavo Mostoslavsky. "The ... -
A Needle in a Base-Stack: Cas9 Structural Biology
TypeBlog Post...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...regions, so crystal structures like those in Figures 2 and 3 don’t show these regions, even if they are present...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,... -
Plasmids 101: Restriction Cloning
TypeBlog Post... 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...containing the ligation mixture with backbone alone; 2. Transformation containing ligation mixture with insert...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...use electro-competent cells instead of the more common chemically-competent cells. You should perform, ... manufacturer’s instructions for your competent cells. For most standard cloning, you can transform 1-... -
No Llamas Required - Synthetic Nanobodies Against Membrane Proteins
TypeBlog Post...select for optimal sybody candidates. Figure 2: Outline of the process for selection of sybodies ...identify and isolate sybodies targeting the SARS-CoV-2 Receptor Binding Domain found on the membrane-bound...Generation Toolbox kit. Find the Seeger lab's SARS-CoV-2 sybodies! References Geertsma ER (2013) FX Cloning...2020) Synthetic nanobodies targeting the SARS-CoV-2 receptor-binding domain. BioRxiv. https://doi.org...Single-Domain Camelid Antibodies. Cell 181:1004–1015.e15 . https://doi.org/10.1016/j.cell.2020.04.031 Zimmermann ...coronaviruses and enable the virus to enter host cells. To do this, they injected the spike protein from...camelid antibodies that bind to the spike proteins in cell culture, and inhibit these viruses. But llama ... -
Year of the Camelid: Antibody Style
TypeBlog Post...and a source of sdAbs (Figure 2) (Xu, et al., 2021). Figure 2: Genetically modified mice offer... from camelid mice and llamas neutralize SARS-CoV-2 variants. Nature 595:278–282. https://doi.org/10.1038...antigens in living cells or tissues. sdAbs can also be used to manipulate cellular functions, like in ...sdAbs over conventional antibodies include: Excellent tissue penetration, thanks to their small size... -
CRISPR-mediated Plant Base Editors
TypeBlog Post...satisfactorily accepts DNA as its substrate (see figure 2). The artificially evolved adenosine deaminase...editing platforms for plant systems. Figure 2: Plant base editor platforms and their molecular components...available for plant systems. Target-AID based (CBE-2)- and rAPOBEC based (CBE-1)- CBEs are successful...based CBEs are known to deaminate cytosine placed in 2-6 bp and 4-8 bp, respectively, of the protospacer....PMID: 27096365. PubMed Central PMCID: PMC4873371. 2. Nishida, Keiji, et al. "Targeted nucleotide editing...homology-directed repair (HDR) pathway which occurs in cells at low frequencies and relies on the efficient delivery...Later the resultant U-G pair is either repaired by cellular mismatch repair machinery making an original C-G... -
Early Career Researcher Toolbox: Social Media for Scientists
TypeBlog Post...scientists are using social media professionally, and 2) I needed to start using Twitter. Sharing Chemistry...but my consistent writing for the Addgene blog (~1-2 blog posts per month) and use of Twitter and LinkedIn...PhD 👩🏾🔬💜 (@ThePurplePage) February 13, 2014 2. "The Scientist's Top 10 Guide to Twitter" blog post...you social media can positively impact your career, 2) given you tips for using various social media platforms...Science Communication” at the American Society for Cell Biology (ASCB) 2018 Conference. I don’t exactly ... -
Truncated gRNAs for Regulating Gene Expression
TypeBlog Post...the absence of genome editing (Fig. 2 and 3) (5, 3). Figure 2: Gene activation with nuclease-competent...shown to exhibit more limited activity than SpCas9 (2). In many cases this is due both to lower relative...PMID: 24076762. PubMed Central PMCID: PMC3844869. 2. Chari, Raj, et al. "Unraveling CRISPR-Cas9 genome... genetic loci within a single cell. One might imagine transfecting cells with both the nuclease-positive...nuclease-competent Cas9, obviating the need to generate new cell lines or transgenic animals expressing dCas9 as ...reliance on orthogonal Cas9 species. Within a single cell, full-length guides targeting one set of genetic...knockin mice for genome editing and cancer modeling." Cell 159.2 (2014): 440-455. PubMed PMID: 25263330. PubMed... -
Lentiviral Vector Uses and Overview
TypeBlog Post...create the 2nd-generation lentiviral system (Figure 2). The HIV genes that do remain are very important ...1996 Apr 12;272(5259):263-7. PubMed PMID: 8602510. 2. A third-generation lentivirus vector with a conditional...CH, Humeau LM, Rebello T. J Gene Med. 2013 Feb;15(2):78-82. PubMed PMID: 23322669. 6. Genetic treatment... Banasik MB, McCray PB Jr. Gene Ther. 2010 Feb;17(2):150-7. PubMed PMID: 19847206. Additional Resources... of cell types, so they’re ideal for work with primary cells or other difficult-to-transfect cells. Lentiviral...dividing cells. Another type of vector, based on adenovirus, could infect non-dividing cells, but without...ability to transduce both dividing and non-dividing cells. Lentiviral vectors are the vector of choice for... -
Tetbow: Bright Multicolor Labeling for Neuronal Tracing
TypeBlog Post...when each of the XFP genes is introduced at ~2 copies per cell per color, following a Poisson distribution...- The XFP genes have to be introduced at ~2 copies per cell per color to achieve the highest color variations...(prepared with Addgene #104110 - #104112) (Figure 2). We’ve also created constructs with containing chemical...imaging with single-cell resolution using chemical cocktails and computational analysis." Cell 157.3 (2014):... optimal expression of XFPs. Any longer and the cells may start to show morphological abnormalities due... wait too long, as too much XFP is toxic to the cells. Inadequate expression levels of XFPs - Reduce the...video below depicting dendrite wiring of mitral cells. Many thanks to our guest bloggers Richi Sakaguchi... -
Optogenetics + CRISPR, Using Light to Control Genome Editing
TypeBlog Post...the light-inducible heterodimerizing cryptochrome 2 (CRY2) and calcium and integrin-binding protein 1 ...inactive, dead Cas9 protein (dCas9) fused to CIB1; and 2) the activator - the CRY2 photolyase homology region... fused to both the N- and C-termini of dCas9; and 2) CRY2FL-VP64, a fusion of full-length CRY2 and the...researchers saw an 11-fold increase in mRNA levels after 2 hr and a 400-fold increase after 30 hr. The system...authors fragmented Cas9 into N-terminal (residues 2-713, N713) and C-terminal (residues 714-1368, C714...nMagC714 instead of nMagHigh1-C714, generating paCas9-2. This change did not significantly alter the system...prior work, the Sato lab also showed that the paCas9-2 system could be spatially controlled and reversibly... -
Mouse Modeling, Part 2: Breeding and Crossing Mice
TypeBlog Post...detect your targeting vector or gene of interest. 2. Breed your parental mice to generate F1 Once you’...strain, the promoter being used should be tested in cell lines to determine how it impacts the expression...interest. Cre may be expressed globally (in every cell of the mouse) or in a tissue-specific manner (with... -
Tips for a 1st time AAV user (by a Rookie AAV user)
TypeBlog Post...then packaged into AAV’s protein shell, or capsid; 2) the pHelper plasmid which expresses adenovirus genes...takes ~3 hours to complete: 1 hours hands-on time and 2 hours for the qPCR run and data analysis. Refer to...quantification of adeno-associated virus serotype 2-derived inverted terminal repeat sequences. Human ...therapy methods, 23 1, 18-28. PubMed PMID: 22428977. 2. Choi, V.W., Asokan, A., Haberman, R.A., & Samulski...packaging AAV is transfecting HEK293 cells with AAV packaging plasmids. The cells need three different plasmids...precipitation. Instead of sonicating the cell pellet, I lyse the cells with this AAV lysis buffer and freeze...bath to release the virus particles from the cells. Cell lysates are then treated with benzonase immediately... -
Viral Production at Addgene
TypeBlog Post...digital PCR. Human Gene Therapy Methods, 25(2), Article 2. https://doi.org/10.1089/hgtb.2013.131 Wang,...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 ... preparations are added to cells in culture. Three to five days later, cell cultures are inspected for...a new vial of early passage cells. Approximately two weeks post-thaw, cell culture supernatant is tested... (55634-AAVrg) alone at 1.7E6 viral genomes (vg)/cell, pAAV-CAG-FLEX-rc [Jaws-KGC-GFP-ER2] (Addgene 84445...preparations ("-LV” catalog items) are produced in 293T cells using the 2nd generation psPAX2 and pMD2.G packaging... -
Hot Plasmids: Spring 2025
TypeBlog Post...imaging and loose-seal, cell-attached recordings in primary visual cortex (V1) layer 2/3 (L2/3). B) Fluorescence...protocols for viral generation and stable cell line creation (Figure 2). Looking for more? Explore our empty...a protein core, 2–4 glycosaminoglycans (GAG), and are (typically) tethered to the cell surface by a GPI-anchor... Lentiviral backbone plasmids here! Figure 2: Addgene cloned EGFP into pAG Lenti CMV N-HA Puro ...either the optogenetic activator channelrhodopsin-2 or fluorescent reporter dTomato under the control ...PV-positive cells out of all BiPVe3-dTom cells. C) Confocal stack of a biocytin-filled cell expressing ...particles in HEK293T cells with pMD2.G (Addgene #12259) and psPAX2 (Addgene #12260). HeLa cells were infected...