...Our educational content  Have you ever wondered how we choose topics for the Addgene blog? Or why we...everything else we do! The goal of Addgene’s educational content Addgene truly believes that sharing speeds...antibody and content team, we identified what applications should be included and what basic information... The guide was then assigned to our science communication specialist, Rachel, to write. Identify expertise...through an editing process and final check before publication.   Do research! Nearly everything we write entails...Guide figures. This requires a fair amount of communication between our content team and our graphic designer...graphic designer upon request that the science communicator "just sketch a western blot out quickly." Final...

...thing that comes to mind. However, ion-based communication is not just for neurons. Non-neuronal cells ...It's just that for non-neural cells, ion-based communication happens at a slightly slower scale.  All living..., and when gap junction-mediated electrical communication is briefly inhibited in the entire worm during...reporting and genetically encoded fluorescent voltage indicators (GEVI) are ideal tools to track bioelectric states...activated proton pump) and ChR2 (blue-light activated cation channel) light-activated channels to hyperpolarize...channelrhodopsin used as a sensitive fluorescent voltage indicator with near-complete desensitization in continuous...extremely exciting emerging field, with many implications for regenerative medicine, evolution of body...

... every genomic locus, and to do so in vivo. Catalytically dead Cas9 (dCas9) cannot induce gene editing...Cas9 ortholog, and the target sequence must be located adjacent to that PAM. To scale up fluorescent CRISPR...this rainbow of colors, Ma et al. performed sophisticated tracking of multiple chromosomal loci in live... do not induce genome editing. If used with catalytically active Cas9, the short, CRISPRainbow gRNA will... PMCID: PMC3918502. Find plasmids from this publication at Addgene. 2. Ma, Hanhui, et al. “Multicolor...PMCID: PMC4364232. Find the plasmids from this publication at Addgene. 3. Ma, Hanhui, et al. “Multiplexed...PMCID: PMC4864854. Find the plasmids from this publication at Addgene. 4. Kiani, Samira, et al. “Cas9 gRNA...

...from the serum. Protein A/G purification Protein A or Protein G purification is one common method. These...reagent that works for your species. Affinity purification Only up to 5% of the IgG antibodies produced...specific for the immunogen. A different type of purification can be performed to isolate antibodies only ...inexpensive. Their short production time and the bulk purification steps keep the cost low compared to other antibody...are particularly useful for certain research applications. Many secondary antibodies are polyclonal, as...target protein thereby greatly increasing signal amplification.  When to stay away from polyclonal antibodies...2018-0065 Fishman JB, Berg EA (2019) Antibody Purification and Storage. Cold Spring Harb Protoc 2019:pdb.top099101...

... antibodies may be indicated on occasion, usually after other signal amplification techniques have been...IgG2 or IgG4. This can be important for some applications. Assay use While secondary antibodies are useful..., the flexibility of their use varies across applications. Western blots, for instance, almost always ...For the latter three, secondary antibodies are indicated when the protein of interest is found in low amounts...been ruled out.  Ease of access Signal amplification isn’t the only benefit of secondary antibodies. Finding...quantitative analysis of a sample. Instead, relative quantification can be done using either the direct or the ...antibodies remain the go-to option for signal amplification while providing needed flexibility in assay ...

... work around this is to "domesticate" your fragment: PCR-based amplification can be used to create silent...and exciting applications, this system is an incredibly powerful tool for cloning complicated constructs...Type IIS sites (such as BsaI or BbsI), that are located on the outside of the cleavage site. As a result...plasmid (Option 1) or added using PCR-based amplification (Option 2). Advantages of Golden Gate cloning...restriction sites that may not be amenable to "domestication", you might want to consider using an alternative...high-efficiency step. References: Sequential amplification of cloned DNA as tandem multimers using class-IIS...

...mammalian cells often relied on chemical (CaCl2, cationic liposome) or electrical (electric current forming...particles and the virus particles produced could not replicate. However, Mother Nature found a way to re-create...packaging plasmid forming a vector that could create replication competent virus. Even though this system was ...still a potential risk for the generation of replication competent lentiviruses (RCL) especially if you...factors in HIV positive cells could make the virus replication competent. The 3rd generation of lentiviral...transgenes (>8 kb) Potential for generation of replication-competent lentivirus (RCL) Efficient gene transfer...transfer Potential for insertional mutagenesis: Replication-incompetent lentiviruses with human tropism can...

...promoter, such as the truncated tyrosine hydroxylase (TH) promoter for catecholamine neurons or glial fibrillary... Flp), to either flip or excise a gene that is located between them. Early recombinase-dependent vector...expression profile at multiple steps from plasmid amplification in bacteria to transgene expression in vivo.... the level of spontaneous recombination. This indicates that the amount of leaky expression can largely...are typically employed during viral plasmid amplification (Fischer, KB. 2019). This means that all DIO...of spontaneous reversion during AAV plasmid amplification. On the left homologous pairs of scrambled cre-recombinase...expression of receptors, post-translational modifications, and other factors that AAV utilizes to gain...

... a calcium sensor Genetically encoded calcium indicators (GECIs) are fluorescent proteins linked to calcium...in living cells and organisms. Unlike chemical indicators, these DNA constructs can be delivered to intact...the sensors discussed below fall into this GECI category.   For calcium sensors, one size doesn...:509-18. Inoue M. Genetically encoded calcium indicators to probe complex brain circuit dynamics in vivo...Kanemaru K, Iino M. Genetically encoded fluorescent indicators for organellar calcium imaging. Biophysical journal...neuronal activity with genetically encoded calcium indicators. Cold Spring Harbor Protocols. 2012 Jun 1;2012...signaling using genetically targetable fluorescent indicators. Nature protocols. 2006 Aug;1(3):1057-65. Resources...

...host genome, the virus is replication incompetent, meaning it can’t replicate and continue the infection... tools, thought was given on how to keep the replication of virus and its infectivity in check. Engineering...envelope plasmid), and the polymerase (Pol) for replication and Gag structural protein on yet a third plasmid... this safety feature prevents the virus from replicating and spreading in non-target cells, including ....    Viral cargo-specific safety   After replication competency, the second concern with virus safety...diseases in humans, earning this virus a BSL-2 classification. Lentivirus (a type of retrovirus) and gamma...decontaminating liquid waste, remember that the percentage indicates the proportion of the decontaminate in the waste...

...another method for making targeted modifications. A recent publication by Zhang et al. shows just that -...about a month and a half, without the need for complicated cloning of homology arms. MMEJ: An Introduction...required by MMEJ can easily be added via PCR amplification. Given the inefficiency of HDR for knock-ins... and 3’ junctions, respectively. These results indicate that PITCh is a robust method for genomic insertion...lies in the diversity of nucleases and their applications. It will be interesting to see what new editing...PMID: 26678082. Find the plasmids from this publication at Addgene. 2. Dalvai, Mathieu, et al. (2015...633. PMID: 26456817. Find plasmids from this publication at Addgene. 3. Zhang, Chi, Xiuhua Meng, Xiaolei...

...well as suitable applications. Expression System Components of System Application Mammalian expression...CRISPR mammalian expression systems, the typical applications for each, and potential delivery methods.   ...Select the appropriate CRISPR tools for your application: Wildtype Cas9 or Cas9 nickase are appropriate... or introducing mutations and tags, while a catalytically dead dCas9 can be used in conjunction with activator...or more sgRNAs and Cas9 are required for any application. If you want to include a homology directed repair...Cas9-gRNA complex and delivered to cells using cationic lipids. Transient expression of CRISPR components...below: Chemical transfection   Lipid mediated Cationic polymers Calcium phosphate Cells Transformed...

...up. Applications of photoactivatable fluorescent proteins Some of the most important applications for ...conventional FP imaging. PA-FPs are divided into 2 main categories - those with irreversible and reversible photoactivation...photoactivation - and have enabled sophisticated imaging techniques.     Irreversible photoactivation Irreversible...level of background fluorescence. For any PA-FP application, the brighter the fluorescence the better. More...photoactivation. A high contrast ratio usually indicates that a PA-FP has a low level of spontaneous fluorescence...photostable green and red states. Beyond these imaging applications PA-FPs have been developed for use in yeast,..."Photoactivatable genetically encoded calcium indicators for targeted neuronal imaging." Nature methods...

...and late gene transcription) is demarcated by viral genome replication (Harrach, 2014). Given that the...encapsidate new virions) are not expressed. Note that replication-competent AdV vectors also exist and are used...the final topic, which is that natural AdVs, replication-competent viruses with a recombinant genome, ...Hermiston, T. W. (2003). Multigene expression from a replicating adenovirus using native viral promoters. Mol ...does not require de novo viral gene expression: Implications for gene therapy. Proc Natl Acad Sci U S A, ...in vivo and maintain activated CD8+ T cells: implications for their use as vaccines. Blood, 110(6), 1916...on the Addgene blog Viral Vectors 101: Viral Applications Adenoviral Vector Production and Troubleshooting...

...drives and their ramifications. Readers unfamiliar with academia’s challenges with publication and funding ...Connecticut College who has been teaching and communicating science for over two decades, attempts to answer... primarily on fluorescent proteins and their applications, tackles much broader issues in this brief volume...sexism in science, problems with peer-reviewed publications and funding, bioethics in the age of CRISPR,... and her essential-but-unlauded role in the identification of DNA’s double helix. Perhaps to the dismay...dismay of middle-aged scientists, the identification of Green Fluorescent Protein (GFP) and its development...CRISPR of course address some of the ethical implications of using these technologies, but also the rapidity...

...helps us to locate interesting addresses in the genome. Let’s now examine how we can locate powerful stretches..., start, and stop. For instance (chr3, 1, 10) indicates a stretch of DNA at the very beginning of the ...for the genome" techniques Technique What It Locates ChIP-seq Proteins (for our example later, histones...therapeutics. We’ll have more to say about clinical applications of CRISPR in the next section. In order to denote...’s associated histone proteins K4 and K27 – locations of the amino acid lysine in H3 me1, me3, and...aceylation, respectively (these are chemical modifications, or functional groups, found on lysine) Putting...blog biobabel blog Resources on the Addgene Blog Catch Up on Your CRISPR Background with CRISPR 101 Learn...

...lentiviral plasmids created for a variety of applications including cDNA expression, shRNA-mediated knockdown... looking for some additional information or clarification on these vectors. Read on to find the answers... thus decreasing the probability of creating replication-competent lentivirus (RCL) in your target cells...type or tissues; this is useful in gene therapy applications where a distinct subset of the cellular population...needs to be targeted. Q6: Are transfer plasmids replication competent? What is SIN? A6: Most (if not all)...all) Addgene transfer plasmids are replication-deficient meaning they can be used to create virus that is...Which genes are deleted or modified to result in replication deficiency? What percent of the vector components...

...immunoprecipitation applications, but none of the traditional tags were suitable for both applications. To prove...from non-vertebrate systems. Preliminary testing indicated that inntags IT5, IT6, and IT10 expressed well...and the chaperone Ydj1, both of which display sophisticated interactions with multiple other proteins. Again...detrimental effects on cell size and growth rate, indicating that they compromised protein-protein interactions...These tags are easy to use in multiple common applications. Due to their limited effects on native protein...particularly in single-molecule or high-throughput applications. Perhaps IT5 and IT6 will even replace our older...

...Labor’s general guide to the effect on higher education, you can see that those in teaching roles (such...frankly quite surprising. Consortia of higher education institutions submitted letters to the Department...centrally administered, which leads to many complications, including the inability of some institutions...paid. Institutional salary policies are one indicatator of how salaries may changes due to the FLSA. ...of the postdoctoral workforce. Based on our communications with and research on these institutions, we...to the new level:  We are still waiting for an indication of what (most of) Harvard, Johns Hopkins, (most...writing responses to requests for the legal justification of this have not been received. Future actions...

... OriP and induces amplification of the episomes concurrently with DNA amplification in the host cell. ...possibilities for the clinical and therapeutic applications of iPSCs. The generation of human iPSCs (hiPSCs...hiPSCs, reprogramming methods that do not involve modification of the original genome by integrating viral ...where each vector contains a viral origin of DNA replication, OriP and the EBNA-1 sequence that encodes for...are necessary and sufficient for retention and replication of the vectors in human cells [8]. The EBNA-1...cocktail. pCXWB-EBNA-1 lacks oriP and is unable to replicate in human cells, thus expressing additional EBNA...., Recent technological updates and clinical applications of induced pluripotent stem cells. Korean J ...