We narrowed to 846 results for: CAL;
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TypeBlog PostPublishedOct. 11, 2018, 12:30 p.m.... more than 10 modules often rely on two-step hierarchical approaches using different Type IIS restriction...stability, and buffer compatibility have placed practical limits on single- or two-step assemblies. We have... While T4 DNA Ligase, the mainstay of most biotechnological cloning efforts for over 50 years, prefers... plate Fidelity of assembly (percent correct) Calculated colony totals Per 2 μl assembly reaction Per...outgrowth volumes described in Figure 3, with calculated yields from entire outgrowth built from 2 µl ...
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Cloning Mammalian Cells with the Agarose Method
TypeBlog PostPublishedSept. 7, 2017, 12:17 p.m.... molecular biology-grade agarose containing physiological concentrations of salts and glucose. If we circled...fluorescent protein), fluorescence microscopy can theoretically be used to select specific wells from the 48... terms of growth rates, morphology or other physiological properties. An advantage of this technique is...properties, either initially, or using secondary biological screens. For example, for cancer researchers,...Neurobiology and Anatomy at the University of Maryland Medical School in Baltimore. She is particularly interested... -
Antibodies 101: Flow Compensation
TypeBlog PostPublishedMay 16, 2024, 1:15 p.m....BV510 and AmCyan have almost identical emission spectra but may be called BV510 on one cytometer and AmCyan...for one another. This overlap in spectra is often called "spillover." For example, if your flow cytometer...shift towards the X axis to become a perpendicular vertical line. In general, most spillover between samples...research technician in Arlene Sharpe's lab at Harvard Medical School. More resources on the Addgene blog Introduction... -
Adenoviral Delivery of CRISPR/Cas9 Aims to Expand Genome Editing to Primary Cells
TypeBlog PostPublishedDec. 10, 2020, 1 p.m....introducing the delivery method in 2014, Manuel Goncalves lab report that AdV-mediated transduction of gRNA...Gonçalves and his colleagues at Leiden University Medical Center are now available at Addgene along with ...and very efficient introduction of DNA into therapeutically relevant, non-transformed mammalian cells. ...and used AdV vectors to edit genes in several biological systems. It has been used for instance in inherited...Viral vectors for gene therapy: Current state and clinical perspectives. Biochemistry Moscow 81:700–708 .... -
Plasmids 101: Optimizing Plasmid Yields
TypeBlog PostPublishedMay 26, 2016, 2:30 p.m....in-house protocol. DNA yields for this procedure are typically in excess of 100 ng/ul, more than enough DNA to...be viewed more as a guideline, since they are typically based on the copy number of the empty plasmid ...improved plasmid DNA yield. Culture conditions play a critical role in plasmid DNA yield. Different plasmids ...are generally, but not perfectly, correlated. Typical growth times for high copy plasmids in standard...miniprepping at various time points. Measuring the optical density of the culture can indicate the number ... -
Summer SciComm Series: Modes of Communication
TypeBlog PostPublishedJuly 1, 2022, 1:15 p.m....Ample distribution channels both digitally and physically. Easy to incorporate visuals if needed. Traditional...means of scicomm. Digital or print distribution. Typically limited to a single page of information. Primarily...levels and interaction. Can bring in things to be physically interacted with. Public speaking is a common ...internet access. High probability of real-time technical difficulties Exhibits Medium to high Audience...exhibit). No remote access; limited occupancy. Typically needs to be staffed. Mixed Media Medium to... -
Introducing Addgene's New Search - Find Plasmids More Easily For Your Research!
TypeBlog PostPublishedDec. 3, 2019, 11:38 a.m.... and ways to navigate it, we’ll search for the calcium biosensor, GCaMP, and click through to the plasmid...distribution. If your experiment involves delivering a calcium biosensor using AAV, you might decide you’d really...? The available filtering options now change dynamically based on the type of material and specific search..., followed by a convenient table of plasmids specifically designed for this purpose: Still stumped? Ask...results at all, let us know! Contact our scientific technical support at [email protected] and let us help. ... -
Plasmids 101: Secondary Nanobody Toolbox
TypeBlog PostPublishedFeb. 27, 2018, 2:04 p.m.... of these techniques have in common? They all typically require secondary antibodies, frequently of the...are derived from an unusual type of IgG antibody called a heavy chain antibody (HCab), which are unique...different species, nanobodies are useful for colocalization labeling of up to 3 targets (Pleiner et al ...desired fluorophores. In figure 4B below, triple colocalization is possible even when staining cells with three...multi-color staining workflow yields similar localization patterns as cells stained for one target (compare... -
SciComm: Taking Science to Elementary and Middle Schools
TypeBlog PostPublishedJuly 9, 2019, 12:52 p.m.... science teachers at our school put out the call to local parents who would feel comfortable speaking ...parents who can answer some of the surprisingly technical questions elementary students can ask. It doesn... dangers of people using the technology in an unethical manner, but I also tried not to be an alarmist...fields in biology, are moving so quickly that it’s basically impossible for textbooks to keep up. Even the ... -
A Career in Grants: How To Become a Grant Professional
TypeBlog PostPublishedAug. 20, 2015, 2:30 p.m....especially in the sciences and by extension to scientifically oriented nonprofits. Like Deb, I worked for...available through not-for-profits, universities, local and national government offices, schools, healthcare... arts? Do you find satisfaction in helping your local food shelf raise money? Do you have experience with... as a grant writer and/or grant reviewer with a local nonprofit that aligns with your passion to get grant...Join the Grant Professionals Association (GPA) local GPA Chapters, and the National Grants Management... -
Harnessing TnpB for Genome Editing: A Compact and Versatile Tool for Your Research
TypeBlog PostPublishedJuly 29, 2025, 1:15 p.m.... an exciting class of compact genome editors, typically only around 400 amino acids in size. To give a...target DNA, TnpBs also need a short sequence motif called a TAM (transposon-associated motif), which is positioned...familiar targeting mechanism. Small RNA elements called right-end RNA (reRNA) or omega RNA (ωRNA) guide... a single experiment (Karmakar et al., 2024). Practical Guide: Using pK-TnpB1 and pK-TnpB2 Vectors The...The process for cloning the 20-nt guide RNA is identical for both vectors. Here, we provide a step-by-step... -
Tips and Tricks for Using Golden Gate Modular Cloning (MoClo)
TypeBlog PostPublishedJuly 8, 2025, 1:15 p.m....allows for directional assembly of DNA sequences, called modules or parts. Assembly is dictated by four-...for fresh bacteria. Performing your Assemblies Calculate your volumes As you progress through the MoClo...increase your ligation efficiency, we recommend you calculate the right volume of each plasmid according to ...the equation in Figure 3. Figure 3: Calculation for the plasmid volume for MoClo experiments....high-throughput, we recommend transforming into chemically competent cells in a 96-well PCR plate. Always... -
Plasmids 101: Shuttle Vectors
TypeBlog PostPublishedMay 20, 2025, 1:15 p.m....production of viral vectors typically involves shuttle vectors, also sometimes called transfer vectors. The ...antibiotic works. Another example is Zeocin, a DNA intercalator, which affects all kingdoms of life. Of course...host range plasmids shuttle vectors? While it’s technically accurate to say that shuttle vectors have a “... “broad host range,” these terms are typically used in different (though overlapping) ways. Broad host... -
CRISPR 101: Any Base Transversion Editors
TypeBlog PostPublishedApril 1, 2025, 1:15 p.m....product purity of 66%. Pro tip! Abasic sites are also called apurinic or apyrimidinic sites and abbreviated ...are the same protein!) (Chen et al., 2024). They called their initial editor AXBE, for A → X base editor...in a G → Y (Y = T or C) base editor, which they called glycosylase-based guanine base editor (gGBE) (Tong... Therapeutics team has deposited their editors, called gTBE and gCBE, with Addgene. gTBE can introduce...site A DNA site with the nucleobase removed. Also called an apurinic / apyrimidinic (AP) site. UNG / UDG... -
New CRISPR Tools: Cas7-11 and PASTE
TypeBlog PostPublishedFeb. 17, 2022, 2 p.m....experimental design and its potential for clinical applications. Specifically, efficacy rates of Cas7-11 were reported...current knowledge. The Abudayyeh-Gootenberg lab (also called the AbuGoot lab), a joint lab run by Omar Abudayyeh...originally suspected that this new Cas7-11 might be phylogenetically classified as the more complex Class I systems...switched up the serine integrase for one which can enzymatically take a genetic sequence and integrate it into... -
Viral Vectors 101: Pseudotyping
TypeBlog PostPublishedApril 20, 2021, 2:30 p.m....JAT, Callaway EM (2007) Monosynaptic Restriction of Transsynaptic Tracing from Single, Genetically Targeted...Why pseudotype? Lentiviruses and retroviruses typically target immune cells with their wild-type envelopes...out this review article published in Reviews in Medical Virology (Li et a., 2018). Figure 2:...6178.1997 Wickersham IR, Finke S, Conzelmann K-K, Callaway EM (2006) Retrograde neuronal tracing with a deletion-mutant... -
CRISPR-based Genome Editing Systems For Editing in E. coli
TypeBlog PostPublishedApril 13, 2021, 1:15 p.m....studying biochemistry at the University of Southern California. He is also an intern at the Yang Lab of the ...transposon-encoded CRISPR/Cas systems in bacteria, specifically on optimizing strains with low efficiency. ...of Sciences. He joined Shanghai Institutes for Biological Sciences in 2000 and became a professor in Synthetic...reprogramming of cells to understand the genetic and biochemical mechanisms behind their distinct phenotypes and...generation of engineered cells for green chemistry and biomedical applications. Yiwen Zhang entered the Sheng... -
Plasmids 101: Plasmid Incompatibility
TypeBlog PostPublishedMarch 31, 2020, 1:15 p.m....molecules, forming a “handcuff” structure that physically blocks replication machinery when plasmid copy...It is also worth noting that plasmids can be symmetrically incompatible, meaning that both plasmids are... from the cell with the same probability, or asymmetrical, where one plasmid lost from the cell at a higher...deal with the more sinister plasmids of the microbiological world. (Want to know more about these plasmid...high copy incompatible plasmids that lead to asymmetrical plasmid loss of the usually large, low copy ... -
Designing Your Chalk Talk for the Academic Job Interview
TypeBlog PostPublishedMarch 12, 2019, 1:37 p.m....the Janelia Research Campus of the Howard Hughes Medical Institute. Are you currently on or planning to ...rejection of a model and no clear alternatives. Typically, a research vision is broken up into three aims... basis of a single grant. Either way, think realistically about the time and resources required to feasibly... aims in more depth in the remaining time. The typical chalk talk structure is: What is the big question...the Janelia Research Campus of the Howard Hughes Medical Institute. His interests include the quality control... -
Supporting Reproducibility with a Connected ELN
TypeBlog PostPublishedJan. 17, 2019, 1:38 p.m.... this post I’d like to delve deeper and look specifically at the characteristics and capabilities an ELN...facilitate true reproducibility. The following are critical: (1) connectivity to other data sources used in...likely stored in institutional and lab servers specifically designed to hold large amounts of data. Although...group’s research – it makes no sense and is not practical to move all this data in bulk into a lightweight...lightweight tool like an ELN. It is nevertheless critically important to be able to conveniently reference specific... -
CRISPR 101: Targeting RNA with Cas13a (C2c2)
TypeBlog PostPublishedSept. 21, 2017, 2:07 p.m....post was updated on Jul 27, 2020. CRISPR, and specifically Cas9 from S. pyogenes (SpCas9), is truly an ...specified by the crRNA sequence, it adopts an enzymatically “active” state rather than reverting to an inactive...propensity of Cas13a to bind and cleave RNA non-specifically. The ability of dCas13a to bind target RNA without...modulating splicing, and regulating expression of specifically targeted RNAs. Finally (and perhaps most interesting...observed shRNA off-targets. They subsequently used catalytically inactive dLwaCas13a as a programmable RNA-binding... -
Deciphering the Mysteries of Behavior with Viral Vectors
TypeBlog PostPublishedSept. 17, 2019, 12:40 p.m....regions and allocate specific functions to them. Electrical recordings and lesioning studies have been essential...within the LC of mice. When those neurons are chemogenetically activated, norepinephrine release causes a...an enhanced propensity for movement and activity called locomotor sensitization. This enhanced movement...responsible for the antidepressant effect. To specifically activate the Drd1 neurons, they injected AAV2... "Hypothalamic CNTF volume transmission shapes cortical noradrenergic excitability upon acute stress."... -
Bioinformatics at Addgene
TypeBlog PostPublishedJuly 14, 2022, 1:15 p.m....In Addgene’s early days, we would ‘spot-check’ critical regions of plasmids deposited with us via Sanger...development teams, frequent updates allowed us to scale our lab work as we grew. As the number of deposited...us to switch between executing our pipeline on a local computer or in a cloud environment. Given the throughput...jumping back and forth between running the pipeline locally and in the cloud. Creating a bioinformatics workflow...script file (containing our new process) on our local computer. Eventually, our workflow would handle ... -
To Codon Optimize or Not: That is the Question
TypeBlog PostPublishedNov. 12, 2020, 2:15 p.m....expression limiting regulatory elements or use a non-canonical code (Gustafsson et al., 2004), such as Hoogsten...recognize multiple synonymous codons) may actually be critical for determining the rate of translation. The ribosome...10.1101/gr.139758.112 Mauro VP, Chappell SA (2014) A critical analysis of codon optimization in human therapeutics... GluCl ion channel genes for mammalian cells dramatically improves expression levels. Journal of Neuroscience...synthetic? How Addgene;s dataset reveals trends in biological innovation Resources on Addgene.org Check out... -
Tips for Using FRET in Your Experiments
TypeBlog PostPublishedNov. 5, 2014, 3:41 p.m....FRET during a journal club, my guitarist brain automatically thought about the raised element found on the...interactions in living cells using a microscope. Historically, molecular interactions were detected by indirect...know or interact with each other. FRET reduced the scale of our perception about molecular interactions. ...Periasamy defined FRET as "a distance-dependent physical process by which energy is transferred non-radiatively...FRET) microscopy imaging of live cell protein localizations. J Cell Biol. 2003 Mar 3;160(5):629-33. ... -
Transferable Skills Guide: Conflict Resolution
TypeBlog PostPublishedJan. 4, 2022, 2:15 p.m....set of transferable skills, coupled with your technical skills, can open new career opportunities for ...conflict can also be good. In science, a reviewer’s critical comments on your manuscript is a form of (hopefully...scientist. And some amount of conflict is actually critical in the business world. Companies and organizations...aspects of customer support each team “owns” is critical for day-to-day operations and keeping our customers...especially people with whom you strongly disagree, is a critical component of conflict resolution. Having empathy... -
SARS-CoV-2/COVID-19 Detection Methods Based on CRISPR/Cas
TypeBlog PostPublishedMay 5, 2020, 1:15 p.m.... RT-qPCR tests to diagnose COVID-19 and some serological tests to determine past exposure. However, the...rapid detection. Highlights: Cas13a is not catalytically active in the presence of two or more mismatches... copies RNA targets in a 40 min incubation. A scalable, easy-to-deploy, protocol for Cas13-based detection...available and less expensive. Instead of using the typical PCR machines, the authors use affordable, field-ready..., Acosta-Alvear, D., & Wilson, M. Z. (2020). A Scalable, Easy-to-Deploy, Protocol for Cas13-Based Detection... -
Evolution of Brainbow: Using Cre-lox for Multicolor Labeling of Neurons
TypeBlog PostPublishedApril 24, 2015, 2:39 p.m....insights into the complicated physical organization of the brain and other biological systems. Interested in ...deletions are defined using 2 loxP variants (only identical loxP sites can mediate recombination.) The deletions... preventing further recombination. Brainbow-1.1 scales up the system to four fluorescent proteins, with...homeostasis results from neutral competition between symmetrically dividing Lgr5 stem cells. Snippert HJ, van der... -
Generating Mouse Models Using CRISPR/Cas9
TypeBlog PostPublishedJuly 12, 2016, 2:30 p.m....without their problems, but much genetic and physiological data have been accumulated over the years using...check out our Mouse Modeling blog posts: Part 1: Genetically Engineered Mice and Part 2: Breeding and Crossing...into the oviduct of pregnant females, a technique called Genome editing via Oviductal Nucleic Acids Delivery...small mutations with HDR, when it comes to larger scale genome editing, such as replacement of a mouse gene...nice to your microinjectionist, who has the strategically important job of delivering the payload! Last... -
Addgene Protocols Go Viral: AAV Purification and Titration
TypeBlog PostPublishedJune 13, 2019, 12:19 p.m....lab, or tissue culture as it is commonly called, is a critical tool for many scientists. Mammalian cells...AAV preparation. For detailed instructions and calculations on how to prepare a plasmid stock used to generate...cells provide scientists with the means to study biological processes on the cellular level instead of having...