...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...non-targeting guides, when both are analyzed using the same false-discovery rate cutoff.  Adding safe-targeting...genome-wide CRISPR screens are prone to some of the same flaws as RNAi screens, such as non-specific toxicity...

...still accrue on average 2 to 3 times as many citations as other papers in the same journals! So, is all ... 1 2010 3 Nature  3.3% 10.5%   3.2  9.6 2 2010 167  Nature 3.3%  10.5%  3.2  534.1 3...Microbiology  1.6% 1.2%  0.75   125.3 In figure 2, you can see the full impact from using these weighted...This post was contributed by guest bloggers Samantha Zyontz and Neil Thompson from the MIT Sloan School... Under such circumstances, we would observe this same correlation, but it wouldn’t be causal. To control...Addgene deposits as if they were published in the same journals as those that did make deposits to Addgene...along the way. Many thanks to our guest bloggers, Samantha Zyontz and Neil Thompson. Special thanks to Addgenies...

... PubMed PMID: 22428977. 2. Choi, V.W., Asokan, A., Haberman, R.A., & Samulski, R.J. (2007). Production...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 ...particles that are present in an AAV prep. AAV samples are first DNaseI digested to remove any residual...technology or a TaqMan primer/probe set can be used and samples are quantified by comparing to an AAV standard ...AAV, remember to account for the dilution of the sample for the DNAseI digest. Use good sterile technique...

...Carballosa, et al, (2015) eNeuro, March/April 2015, 2(2) e0001-15.2015. Pubmed. Resources: http://openspim.org...light sheet, typically 2-6  microns, illuminates only one thin plane of the sample surrounding the focal...orthogonal-plane fluorescence optical sectioning (OPFOS) (2). Arne Voie, David Burns and Francis Spelman focused...beam into a thin sheet to illuminate a fluorescent sample and captured the reflected light using a different...laser and the reflected light travel through the same objective lens. Using this method, these authors...problem is to illuminate and acquire images of a sample from two opposing sides and merge the images, such...

...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 ... is included on the gRNA-containing plasmid, or a 2-plasmid system in which Cas9 must be delivered separately...uncontrolled cell growth, such as cancer. Figure 2: The CRISPR library must be amplified (A) to be used...Enrichment or depletion of multiple gRNAs targeting the same gene can be strong evidence that a particular gene...

...procedure to be performed using a simple two-step, 2 hr protocol prior to transformation (Figure 1). As...Primer design Using specific primer design (Figure 2), IVA cloning can be used to perform any plasmid modification... for each type of modification is shown in Figure 2, and is discussed in more detail below. The main requirement...Biotechniques 10.1 (1991): 62-66. PubMed PMID: 2003926. 2. Bubeck, Peter, Monica Winkler, and Wilfried Bautsch...laboratory. All procedures are performed using the same three step protocol:  Fragment generation - Any...events, all linear fragments need to get into the same cell. For simple cloning requiring just one or two...vector and insert with separate primer pairs in the same PCR. Add homologous sequences to one of the primer...

...Analytical Chemistry 27(2):108-117 · February 2008. 11. Svensen, Nina and Jaffrey, Samie R. “Fluorescent RNA... to DFHBI in the presence of that metabolite (Fig.2). Spinach eventually evolved into Spinach2, a more...PMID: 25713381. PubMed Central PMCID: PMC4364232. 2. Baker, Monya. “RNA imaging in situ”. Nature Methods...emerging environmental pollutants.” Front Chem. 2014; 2: 41. PubMed PMID: 25019067. PubMed Central PMCID: ...and subsequently leading to a positive signal. The same effect can be achieved for a fluorophore that relies...context of a paired fluorophore protein. Years later, Samie Jaffrey’s laboratory took advantage of their deep... Jaffrey lab asked:  Could an RNA aptamer do the same thing? Using the HBI derivative 3,5-difluoro-4-hydroxybenzylidene...

...Nature Cell Biology, 26(2), 294–304. https://doi.org/10.1038/s41556-023-01342-2 Koblan, L. W., Arbab, M...order to bind DNA, Cas9 requires (1) a guide RNA, (2) a complementary DNA sequence, and (3) a protospacer-adjacent...region of separate strands called an R-loop (Figure 2). This allows the guide RNA to base pair with the ...accessible on the outside of the enzyme. Figure 2: CRISPR R-loop. Created with BioRender.com. Base...), 35–40. https://doi.org/10.1038/s41587-020-0592-2 Additional Resources on the Addgene blog CRISPR 101... around the same time. (The papers were actually published in the same journal on the same day.) This ... But the same strategy in E. coli produced different results. GBEs seemed to follow the same initial mechanism...

... let the panelists introduce themselves. I do a 1-2 minute introduction. If you chose good panelists, ...take 5 minutes to introduce themselves and, voila, 1/2 of your time is gone with no interesting discussion...introductions. The moderator asks questions, calling on 1-2 panelist for each question in a way that elicits those...shift, they are checking out. If you can, plant 1-2 good questions with trusted audience members. A good...answers uninteresting, the panel members all say the same thing and one panel member dominates the discussion... for an intimate event, put the panelists on the same level as the audience. In my experience the best...

...alkaline lysis plasmid miniprep Starting material: 2 mL bacterial culture Product: plasmid DNA This kit-free...protocol: 1) it solubilizes both DNA and agarose, and 2) it helps DNA stick to the glass. After binding DNA... had a similar level of sensitivity. Figure 2: Steps to purify DNA using a cellulose dipstick. Image...Academy of Sciences of the United States of America, 76 2, 615-9 . https://doi.org/10.1073/pnas.76.2.615  Zhou...of the drawbacks of kits and typically follow the same principles: cells are lysed, RNAs and proteins are... centrifugation. At this point, the plasmid DNA sample can be treated with RNase to remove RNA contamination... buffers ran out. Homemade buffers performed the same as those provided with the kit. Although not tested...

...they wanted to see more negative data (Figure 2.) At the same time, when scientists who support open science...is not only housed, but encouraged.    Fig. 2: Results from a survey conducted by Addgene in 2021...detailed methods and image descriptions, a minimum n = 2, and well labeled high- and low-magnification images...gene therapy trials. Human Gene Therapy Methods, 26(2), 71–76. https://doi.org/10.1089/hgtb.2015.040 Initiative...well for a neighboring cell type, even within the same brain region or nucleus. Just optimizing AAV expression...vectors, many from people trying to answer the exact same question I was: What AAV vector is best for my specific...

...one of lox2272 sites will now be sandwiched between 2 loxp sites and is excised by Cre (Figure 1). This ...flank the transgenes (non-homologous pairs) (Figure 2.). They found that almost all off-target expression...exercise caution when using them.    Figure 2. Schematic diagram showing the mechanism of spontaneous... Tropism and Axonal Transport of AAV Serotypes 1, 2, 5, 6, 8 and 9 in the Mouse Brain. PLoS ONE 8:e76310... Pseudotyped with Viral Capsids from Serotypes 1, 2, and 5 Display Differential Efficiency and Cell Tropism... with the same titer and serotype previously used in a different brain region that the same result will...sites will be flanked by two lox sites now in the same orientation. Next, the loxp site is excised since...

... Figure 2: Due to differences in their size and complexity, cells from a whole blood sample will separate...termed fluorescence activated cell sorting or FACS (2). By analyzing single cells instead of the population...expression. A routine flow cytometry experiment uses 2 or 3 different fluorescent colors each measuring a...distinct populations on a FSC versus SSC plot (Figure 2).  A user can then “gate” around the specific population...cell and T cell into distinct populations (Figure 2). An immunologist who studies B cells, might then ...was raised in the same host species, of the same Ig subclass, and conjugated to the same fluorochrome as...ensure that samples are single cell suspensions. For cells that tend to aggregate, pass the sample through...

...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 ...intracellular signaling pathways. Trends in Biotechnology, 33(2), 92–100. https://doi.org/10.1016/j.tibtech.2014.11.007...

...discussed them in meetings and 2) creating a pictorial guide for our engineers (Fig. 2). Creating this guide was...communication has helped Addgene move from completing 2-3 large projects a year, on average, to completing... and engineers were attending the same meetings and hearing the same words, they were leaving these meetings...aforementioned lab manager, said the word “sample,” did the word convey the same concept to Morgan, our senior engineer...help get everyone on the same page. Others in the meeting might also have the same question and asking can...When everyone at a meeting is using the same words with the same meanings consistently, meetings will be...counsel, used the word “service,” did he mean it the same way as Bryan, our customer support manager? When...

...month, from 1/22/20–2/23/20, where there were zero plasmid requests. Afterwards, from 2/24/20–3/15/20 (the...Each paper has between 1–32 plasmids and a total of 2–2,590 requests. We received plasmid requests from ...observed between Jan. 1 and Mar. 1, 2020. Figure 2: A simple approximation of the effect of COVID-19 ...However, it is evident that if we believe that 1/22/20–2/23/20 are the more accurate dates of lockdown in China...interpretation -- the effect would generally not be the same if weekends were somehow imposed on scientists. ...

...incubation at 37 °C. Wash the membrane for 5–10 minutes 2–3x in fresh wash buffer such as PBS or TBST. Stringent...Purpose Tris HCl 62.5 mM Buffer SDS 2% (w/v) Detergent Β-mercaptoethanol (βME) 100...minutes at 50 °C. Wash the membrane for 5–10 minutes 2–6x in fresh wash buffer such as PBS or TBST. Note ...membrane will remove some of your sample —and harsher stripping means more sample loss. If you are still optimizing...you want to detect more than one protein in your sample? Or what if something weird happened during your..., almost like new. This approach preserves your sample and saves you from having to run a whole new gel...stripping solution (see below) to minimize loss of your sample from the membrane. Next, plan out the order of ...

...FLP and Cre for additional control   Figure 2: Expression of a morphological marker (eYFP) and synaptic...Sternson. 2008. “A FLEX Switch Targets Channelrhodopsin-2 to Multiple Cell Types for Imaging and Long-Range ...PMID: 18614669. PubMed Central PMCID: PMC2593125. 2. Buchholz, F, P O Angrand, and A. Francis Stewart....The FLP Recombinase of the Saccharomyces Cerevisiae 2 Micron Plasmid Attaches Covalently to DNA via a Phosphotyrosyl...reintroduction, inversion and re-inversion happen at the same probability. Continuous inversion of the DNA sequence...recombination can only occur between target sites of the same sequence in FLEx vectors, the DNA sequence that ...neuron and its synapse should be visualized at the same time from two different plasmids this approach becomes...

...sites on the same chromosome. Most multiplex systems enable researchers to target anywhere from 2–7 genetic...protein, instead of a two-component system (Figure 9C) SAM activators - co-expression of dCas9-VP64 with a modified...left free to interact with the target DNA. Figure 2: Overview of the NHEJ repair mechanism Cas9 will only...Cas9 is included in the gRNA-containing plasmid, or 2-vector systems, in which Cas9 must be delivered separately...your experimental cell population (Figure 8E). In a 2-vector system, you’ll need to either co-infect with...the presence of infectious organisms (like SARS-CoV-2 ) and genetic mutations. Similar to Cas9 and Cas12...Cas enzymes? CasPEDIA is an encyclopedia of Class 2 CRISPR systems with wiki entries describing enzyme...

...imaging (Figure 2). If you’re working with purified proteins in vitro, you can even use the same tag for multiple...super-resolution or single-molecule techniques.   Figure 2: Two-color super-resolution imaging of ER and mitochondria...stimulated emission depletion (STED) nanoscopy. Scale bar, 2 μm. Inset shows comparison with standard confocal ...Labeling in Living Cells. Chemistry & Biology, 15(2), 128–136. https://doi.org/10.1016/j.chembiol.2008.01.007...conjugates: A flexible chemical tag. Nature Methods, 2(4), Article 4. https://doi.org/10.1038/nmeth749 Strebinger...sequentially adding different ligands to the same sample to label sub-populations of your protein of interest...probably find lots of different plasmids containing the same protein of interest tagged with different fusion...