We narrowed to 915 results for: Tro;
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TypeBlog Post...delivery include plasmid transfection, RNP electroporation, and viral transduction; but these methods ...gRNAs. Viral envelope proteins To alter the cell tropism of Nanoblades, different viral envelope protein...with a mix of VSV-G and the baboon endogenous retrovirus Rless glycoprotein (BaEVRless) had high rates...gene, while editing was not detected in cells electroporated with RNPs using the same guide. Nanoblades ...influence the level of off-target effects, with electroporation of RNPs generally having lower off-target edits...polymer. Polybrene has long been used to increase retroviral transduction efficiency by neutralizing the charge...the cell surface, and also helps form DNA and retroviral-particle or VLPs complexes. The team found that...
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Split-BioID: An Improved Method for Studying Protein-Protein Interactions
TypeBlog Post... No spatiotemporal control. Many PPI detection methods lack spatiotemporal control or an “on/off switch...identifying PPIs, such as affinity purification mass spectrometry (AP-MS), lack the ability to specifically identify... by creating Split-BioID, a spatiotemporally controllable version of the proximity-dependent biotinylation...method Enter Split-BioID, a spatiotemporally controllable version of the BioID protocol. The critical ...interaction partners if they are enriched relative to controls using Split-BioID-GFP and BioID run on six unrelated...combinations and pick the conditions that give the strongest biotinylation signal, as measured via Western ...methods, including BioID, is its spatiotemporal controlled labeling of interacting proteins; nearby proteins... -
Viral Vectors 101: Virus Safety
TypeBlog Post...classification. Lentivirus (a type of retrovirus) and gamma retrovirus require more caution as they are integrating...virus and its infectivity in check. Engineering controls, safety systems that are built into how something...functions, were designed for this purpose. One such control is dividing up the essential components of a virus...virus into different plasmids. For a retroviral system this looks like the genetic cargo in one plasmid... researcher. Figure 1: Separation of retroviral packaging components onto distinct plasmids for...common types of viruses grown in the lab are gamma retrovirus, lentivirus, adenovirus, and adeno-associated... Susanna Stroik... -
Mobile-CRISPRi: Bringing CRISPRi to Diverse Bacteria
TypeBlog Post...lab-adapted bacteria because it has been challenging to introduce CRISPRi machinery into diverse bacteria species... gRNAs, and dCas9 proteins. Second, it can be introduced into a broader range of bacteria. Once transferred...., 2019 with permission. Two methods to introduce Mobile-CRISPRi by bacterial conjugation For gram...gram negative bacteria, Mobile-CRISPRi is introduced using the bacterial Tn7 transposon system. This system...firmicute gram positive bacteria, Mobile-CRISPRi is introduced using the bacterial integrative and conjugative...Mobile-CRISPRi. The Mobile-CRISPRi ICE element is first introduced into the B. subtilis genome. Mobile-CRISPRi is...into the trnS-leu2 locus. Figure 2: Introducing Mobile-CRISPRi into bacteria. Top: A Tn7 transposon... -
The AAVantages of AAV in CRISPR Screens
TypeBlog Post... Overview of in vitro AAV CRISPR screens. Created with BioRender.com. The in vitro option requires... screens may be AAVantageous! In vivo, in vitro, ex vivo CRISPR screens can be carried out using...using a few different methods — in vivo, in vitro, and ex vivo. The general process of these screens is the...with transducing cells with the CRISPR library in vitro before transplanting them into mice. For in vivo...when designing screens. Each serotype has its own tropism, or a preference to infect specific cell or tissue...tissue types. Using serotypes that have a known tropism for your cells of interest — for example, AAV8 ... used these psuedotypes to further improve the tropism of AAV vectors, enhancing their affinity for specific... -
Viral Vectors 101: Voltage Indicators
TypeBlog Post...action potentials, muscle contractions, and the control of voltage gated ion channels all depend on transmitting...been successful even at the single neuron level in vitro. In vivo monitoring has also been achieved with ...effective at the single cell level as they are in vitro. Factors like photobleaching, lack of red-shifted...rhodopsin. FP-fusion to rhodopsin resulted in electrochromic FRET capable GEVIs, with rhodopsin quenching...membrane as well. Another flavor of these tools is Voltron, which uses rhodopsin as the voltage sensing component...genetically encoded component is delivered in vivo or in vitro and a small molecule is added exogenously to measure...Optogenetics Fluorescent Proteins 101: Introduction to FRET ... -
Antibodies 101: Flow Compensation
TypeBlog Post... APC control, with APC and APC-CY7 plotted against each other. Since it is a single-color control, you...example with single color control. Flow plots showing an APC single-color control sample before (A) and after...recommended to start compensating with single-color controls before moving onto your experimental samples. ...samples without needing to use your single-color controls as a starting point. Applying compensation to ...experimental samples as they did with your single control samples: if the population needs to be shifted ...School. More resources on the Addgene blog Introduction to Gating in Flow Cytometry Antibodies 101: ... -
New Viral Vectors - March 2024
TypeBlog Post...AAV PHP.eB Controls Wilson New viral vector pENN.AAV.EF1a.eGFP.WPRE.rBG AAV PHP.eB Controls Wilson New...pAAV-CaMKIIa-EGFP AAV PHP.eB Controls Roth New serotype pAAV-hDlx-Flex-dTomato-Fishell_7 AAV2 Controls Fishell New serotype... AAV PHP.eB Controls Gradinaru New serotype pAAV-CaMKIIa-mCherry AAV PHP.eB Controls Deisseroth New...New serotype pAAV-Ef1a-mCherry AAV PHP.eB Controls Deisseroth New serotype Looking for more viral... -
CRISPR 101: Ribonucleoprotein (RNP) Delivery
TypeBlog Post...28b-Cas9-His from Alex Schier’s Lab. gRNAs can be in vitro transcribed from ssDNA, which can be generated by... advantage has allowed scientists to perform in vitro and in vivo CRISPR studies in experimental systems... common techniques for delivery of RNPs is electroporation (A in the figure above), which generates pores...through a process known as CRISPR-EZ (CRISPR RNP Electroporation of Zygotes) (Chen et al. 2016). For CRISPR ...CRISPR experiments that involve HDR, electroporation can be combined with cell-type specific reagents in a ...approach using RNPs has recently been described in vitro, with the hope of eventually using this method for...genome editing by CRISPR ribonucleoprotein electroporation of zygotes." Journal of Biological Chemistry... -
Great Results Start with Great Standard Curves
TypeBlog Post...unknown sample. To do this, you serially dilute a control sample of known concentration and measure a specific...example, a BCA assay uses a serial dilution of a control protein, incubated alongside an unknown sample ... absorbance of both is then measured on a spectrophotometer and concentration versus absorbance is plotted... a standard curve by serially diluting a known control sample, called a standard. The ideal standard curve...curve accordingly. Figure 1: A 1 mg/mL control is diluted in a series ranging from 1:2 to 1:32... for each run. To validate, include a positive control of known concentration in the experiment and use... Include both a standard curve and a positive control in every run. When setting up your dilution series... -
Uncovering Ancestral Bias in CRISPR Research
TypeBlog Post...only a few, very strong associations. Unexpected results Their results showed 96 strongly correlated genetic...may be the result of a technical artifact that introduced an ancestry bias into their experiments instead... prevent Cas9 from cutting, both of which can introduce significant bias into the results. But the reference...mapped to a SNP would be ignored. Working with Lia Petronio and Katherine Huang from Broad’s Pattern team,... of ancestral bias into genome-wide screens, introducing bias into all work based on these and any other...an ancestry group what is actually an artifact introduced by bias within the design of the experiment or...Noorbakhsh, Isabella Boyle, Joshua Dempster, Lia Petronio, Katherine Huang, Alham Saadat, Thomas Green, ... -
Save Time and Money by Making Your Own Competent Cells
TypeBlog Post...chemically competent cells (protocol) Preparing electrocompetent cells (protocol) Untergasser Lab Preparation... competent cells (protocol) Preparation of electrocompetent cells (protocol) At Addgene, we use the...Transforming chemically competent cells (protocol) Electroporation (protocol) Untergasser Lab Transformation...competent cells (protocol) Transformation of electrocompetent cells (protocol) Cells prepared using ...with ampicillin resistance. After a plasmid is introduced to bacteria, the bacteria is typically grown ...competent cells, don’t forget to do a negative control (plate your cells without adding plasmid) to make...have contamination. Also conduct a positive control (test a plasmid that transforms well in other competent... -
Let There Be LITE Plasmids
TypeBlog Post...Under those optogenetic controls, gene expression levels reliably increased in vitro by a factor of 10 to...what the LITEs now enable. In a Nature paper introducing the optogenetic tool, Konermann and Zhang showed...populations. They demonstrated use of the LITEs to control gene expression in mouse neurons and in the brains...both quickly and significantly. Genes under LITE control showed a rise in transcription in as little as ...to establish it as “a novel mode of optogenetic control of endogenous cellular processes." The LITE system... Reference: Silvana Konermann et al. "Optical control of mammalian endogenous transcription and epigenetic... -
Save Time with Transient Plant Leaf Transformations
TypeBlog Post...tobacco. Studying gene function in C. roseus is strongly limited by the availability of methods. Infection...check for GUS-like activity of your tissue. Run a control with Agrobacterium lacking the GUS gene since plants...promoter activity, for example. Useful positive controls could include: pSB96 - pL2_pSB90_2x35S::fLUC-I...days in the dark after the transformation. Use introns Plant promoters can be recognized or leaky in Agrobacterium...Agrobacterium, but not the plant. For example, we have seen strong expression of the GUS gene with the commonly used...Agrobacterium. This can be easily avoided by the use of introns, which will be removed from the transcripts in ...plants, check out this interview with the Nicola Patron, who shared the MoClo plant kit via Addgene. For... -
New Tools Enable CRISPRa for Neuroscience Applications
TypeBlog Post...spatiotemporal control over its expression. Constitutive or inducible Cre recombinases can be introduced by AAV...SPH mice CRISPRa has largely been limited to in vitro settings due to the large size of Cas9 activators...in vivo, they should be screened for activity in vitro and then packaged into AAV for in vivo delivery....developed neuron-optimized lentiviral vectors for in vitro and in vivo CRISPRa (Savell et al., 2019). This ...immediate-early gene Bdnf, which encodes brain-derived neurotrophic factor (BDNF). Bdnf is expressed early in response...of other CNS cell types, including microglia, astrocytes, and oligodendrocytes, provided that reporter...preferable for individual gene activation in select in vitro and in vivo applications, the tools described above... -
Plasmids 101: Shuttle Vectors
TypeBlog Post...the vector to survive while the auxotrophic cells die. Some auxotrophic selection markers can be used across...autonomously replicating sequence (ARS), a partial centromere sequence (CEN), both, or neither, depending on...autonomously replicating sequence (ARS) a partial centromere sequence (CEN) both or neither ...depending ...choose to ensure it works in your host species! Auxotrophic selection Another option is to use a different...different method of selection entirely. Auxotrophic selection relies on the host organism being unable to synthesize... example, in both S. cerevisiae and E. coli. Auxotrophic selection is especially common in yeast experiments...spontaneously develop resistance to selection toxins. Auxotrophic selection is useful for producing stable mammalian... -
A Needle in a Base-Stack: Cas9 Structural Biology
TypeBlog Post...very weakly, most likely through unstructured electrostatic interactions. It also can’t recognize PAMs, ... present in the sample. Other techniques, like electron microscopy and FRET, can offer more information...well described in the closed conformation, recent electron microscopy studies have also found Cas9:RNA complexes...loops 2 and 3 are not strictly necessary for in vitro cleavage, but they improve cutting efficiency and...pairing in the seed sequence. Figure 6: Electron microscopy structure of S. pyogenes Cas9 bound...structure (left, PDB ID 4ZT0) with Cas9:RNA:DNA electron microscopy structure (right, PDB ID 7S4X), viewed...conformational state of the HNH domain also allosterically controls RuvC activity through a hinge region between the... -
Important Considerations in Optogenetics Behavioral Experiments
TypeBlog Post... Historically, ICSS was done by implanting an electrode and non-specifically electrically stimulating ...opposite chamber) [2]. Laser activation is usually controlled automatically using motion capture software such...apply. Testing stimulation First, In lieu of electrophysiology, it would be convenient to know if you are...targeted brain region after stimulation compared to controls without Chr2. c-Fos is a reliable and widely used...easiest way to resolve these issues is with electrophysiology. Concluding thoughts and moving beyond the...PMC4181379. 3. Kheirbek, Mazen A., et al. "Differential control of learning and anxiety along the dorsoventral ...silencer: development and application to optogenetic control of non-human primate cortex." Frontiers in systems... -
Plasmids 101: Biotinylation
TypeBlog Post...extremely strong affinity for one another. Actually the bond between them is one of the strongest noncovalent...that scientists began to exploit biotin and its strong interaction with avidin for molecular biology and...papers and webpages are listed below: EMSA (Electrophoretic Mobility Shift Assays) ELISA (Enzyme-Linked... biotinylate macromolecules of interest both in vitro and in vivo. Biotinylation reagents Biotin’s exposed...attached to a photoreactive arylazide group. Under strong visible light, the arylazide group becomes reactive... Krijgsveld, J., Katsantoni, E., Heck, A., … Strouboulis, J. “Efficient biotinylation and single-step ...Schwartz, S. A. “Biotinylated probes in the electrophoretic mobility shift assay to examine specific dsDNA... -
Identifying Sequence Elements with SnapGene's Feature Database
TypeBlog Post...place the most important controls front and center, and make specialized controls available when needed....sequence and display frequently used genes and control elements. Development of this tool required creating... DNA sequence has changed. Identifying plasmid control elements Coding sequence features are relatively...relatively straightforward to define, but for control elements such as promoters and transcription terminators...obvious. We found that the annotated boundaries for control elements in commercial plasmids were inconsistent...how we use SnapGene during the plasmid quality control process Check out full plasmid sequencing at Addgene... -
Technique: Probe Phage Genomes for Host Binding Proteins
TypeBlog Post...or Salmonella, or any cells that bind strongly to nitrocellulose, over-incubation of plates can lead to...forcing DNA through a small opening using compressed nitrogen gas; this shears DNA at random locations and allows...containers that can easily be attached with a hose to a nitrogen gas tank with a pressure regulator. Other methods...cells, isolated colonies will be lifted onto nitrocellulose membranes and exposed to IPTG in order to induce...release recombinant proteins directly onto the nitrocellulose for subsequent probing for cell-binding activity...First, cut out 20 Petri dish-sized circles of nitrocellulose membrane and press each gently down onto a ... helpful to spot this protein directly onto nitrocellulose and carry out the steps from blocking the membrane... -
Generating Mouse Models Using CRISPR/Cas9
TypeBlog Post...1980s, gene targeting technology was invented to introduce specific changes into the mouse genome. With these... early technologies, a researcher would first introduce a mutation into a mouse embryonic stem cell (ESC...chromatogram showing the telltale signs of a mutation introduced by CRISPR. The sequence started clean and then...handling embryos ex vivo, the components can be electroporated into the oviduct of pregnant females, a technique...gRNA, Cas9, and donor oligonucleotide can be electroporated into the mouse zygote (Qin et al., 2015). ...targeting. CRISPR tools were recently used to introduce a 25 kb human gene into the mouse genome. However...Goodwin LO, Morgan JL, Juan WC, Roca X, Ong ST, Bergstrom DE (2018) Viable Mice with Extensive Gene Humanization... -
Plasmids 101: Restriction Cloning
TypeBlog Post...on the left, your digested DNA (and undigested controls) are loaded at the top of the gel in wells positioned... uncut sample of each plasmid to help with troubleshooting if your digests don’t look as expected. Once...to insert. It is critical to set up a negative control ligation reaction with no insert DNA added. This...much less total DNA (<1ng) or if you are having trouble getting colonies, you might want to use higher ...to be very large (>10kb) you might want to use electro-competent cells instead of the more common chemically-competent...minimum, two transformations after a ligation: 1. Control Transformation containing the ligation mixture ...see any colonies, you should conduct a positive control to ensure that your transformation worked. You ... -
New and Upcoming Viral Vectors - September 2019
TypeBlog Post...will continue to add more controls, and have recently released these controls: pAAV-hSyn-DIO-EGFP (50457...sensors Optogenetics Recombinases And more! Control AAV For many AAV experiments, we recommend validating...aliquots in AAV1, AAV2, AAV5, AAV8, AAV9, and AAV Retrograde. You can also request the specific serotypes ...entire collection! We are expanding our entire control AAV inventory to give scientists access to a wide...AAV5 and 112677-AAVrg): The EF1a promoter directs strong, ubiquitous expression. This is a Cre-dependent... Email us or check our website to access them! Controls pAAV-hSyn-hChR2(H134R)-EYFP (26973-AAVrg) pAAV-hSyn-hChR2... -
Addgene-Seeding Labs plasmid grant round 3: microbial drug resistance and biofilms, antidiabetic plant components, visualizing brain injury - and a glowing robot fish
TypeBlog Post...etiopathomechanisms of ischemic stroke, the most common type of stroke and the third leading cause of ...-Seeding Labs plasmid grant we are excited to introduce the 5 awardees and their research. These researchers... is necessary to improve tuberculosis care and control. In her current research, Sheen aims to identify...taraxacifolia (Willd), an annual herb of Western Tropical Africa typically known as wild lettuce. Aside ...of death and disability worldwide. An ischemic stroke occurs when arteries leading to the brain become ...of interesting combinations: biomedicine and astrobiology. During the last 11 years he has studied various... -
15 Years of Addgene: The Top 15 Plasmids
TypeBlog Post...generation lentiviral packaging plasmid from the Didier Trono lab that expresses the HIV gag, pol, rev, and tet...pMD2.G. Find psPAX2. pMD2.G - Also from the Didier Trono lab is pMD2.G, a VSV-G envelope expressing plasmid...envelope protein for producing lentiviral and MuLV retroviral particles. It can be used with packaging plasmids...as pCMV-dR8.2 dvpr (lentiviral) or pUMVC (MuLV retroviral). Fun fact: published in 2003, this plasmid predates...generation lentiviral packaging plasmid from the Trono lab contains the rev gene. It’s meant to be used...generation lentiviral packaging plasmid from the Trono lab that contains the gag and pol genes. It also...shRNA. This scrambled shRNA is used as a negative control for mammalian RNAi experiments. Find the scrambled... -
Antibodies 101: Isotypes
TypeBlog Post...you can select an appropriate isotype control. An isotype control has the same constant heavy chain domain...heavy-chain constant region (see Antibodies 101: Introduction to Antibodies for a refresher). There are five...molecules are recruited by the antibody to help destroy and remove a pathogen. Different isotypes also ...doesn’t bind your antigen of interest. Isotype controls are used to make sure the staining you see is ... than nonspecific background staining. Isotype controls are used in antibody-based applications including...techniques that you can use antibodies for in our Intro to Antibodies post Check out our Antibodies 101:... -
Viral Vectors 101: Biosensors
TypeBlog Post...The calcium is strong here….I can sense it….sound like a plot to an biology scifi movie? Or maybe it’...neurotransmitter, such as norepinephrine, or an electrolyte such as calcium. This varied component, which...For one, many viral platforms, such as AAV or retrovirus, can either permanently integrate and/or express...serotypes can be used to affect or determine viral tropism—the type of cells the viral particles infect. This... sensor, whether you choose lentivirus, gamma retrovirus, or AAV as your vehicle, we’ve got you covered...Resources References Bhalla N., Jolly P., et al. Introduction to Biosensors. Essays Biochem. 2016 Jun 30;60... Susanna Stroik... -
CRISPR 101: Non-Homologous End Joining
TypeBlog Post...consequently the principal means by which CRISPR/Cas9-introduced breaks are repaired. The following factors are...ends tends to be the point where mutations are introduced. Repair of Cas9-induced breaks by NHEJ As illustrated...microhomologies”). NHEJ doesn’t obligatorily introduce indels. Given the end structure of the Cas9 DSB...hundreds of base pairs or more can simultaneously introduce a pair of chromosome breaks, and could result ...single strand break; when two such breaks are introduced near each other, in opposite strands. This “double...j.cell.2013.08.021 Waters CA, Strande NT, Pryor JM, Strom CN, Mieczkowski P, Burkhalter MD, Oh S, Qaqish BF...Video] Pooled CRISPR Libraries Offer Genome-Wide Control for Large-Scale Functional Screens ... -
When Fidelity Matters: A frank discussion about ligase fidelity
TypeBlog Post...phosphorylated DNA termini to 3 ́-OH DNA termini (1-4). In vitro, ligases (notably T4 DNA ligase) are critical reagents...circularization of dsDNA (6). Less commonly utilized in vitro, Taq DNA ligase will ligate only nicks (5-8). Taq...identifiable and quantifiable by capillary electrophoresis (CE) (see below). This method allowed screening...gene PCR-ligase detection reaction-capillary electrophoresis assay." Journal of clinical microbiology 45.6...PMC1933048. 16. Cheng, Changming, et al. "Electrochemiluminescent assay for detection of extremely rare mutations...mixed population of excess wild‐type DNA." Electrophoresis 34.9-10 (2013): 1415-1422. PubMed PMID: 23463388... PMID: 17466627. 25. Luo, Jianying, Donald E. Bergstrom, and Francis Barany. "Improving the fidelity of... -
Antibodies 101: Validation
TypeBlog Post...that antibody works as expected, you will see a strong antibody signal in the retinal sample, but little...you see a similar antibody signal between your control and your knock-out sample, you should be concerned...antibody binding in the transfected cells but not in control cells. But (there is always a ‘but’), you should...encoding this protein, which we will call Negative Control Gene (NCG) (A). Then you lyse the cells and run... your antibody (B). Your results show a lovely, strong band from the cells transfected with your protein...well as a third unrelated antibody as a negative control (A). The two antibodies to your protein of interest...sample using the antibody and then uses mass spectrometry to identify the captured proteins. If the antibody... -
9 tips for a successful postdoctoral experience
TypeBlog Post...anticipated outcomes? What are your controls? Will these controls enable you to interpret your results...e.g. an R01 from the NIH, in the United States) Strong letters of reference that attest to your talent...figures are missing? For example, are additional controls necessary? As you build your story, are additional...person makes time for you, as needed, this is a strong indicator that this person cares about your science... together, all of this means that you need to introduce yourself to and talk with more senior scientists...you and your research exposure. Use meetings to introduce yourself to and interact with the members of your...Medical Institute. His interests include the quality control of secretory proteins in the Endoplasmic Reticulum... -
Plasmid Tools for Microbiome Studies
TypeBlog Post...identified seven genera in in vitro experiments, possibly because in vitro conditions did not optimally...situ Conjugation (MAGIC). With MAGIC, scientists introduce an Escherichia coli donor strain into the microbiome...antibiotic selection. The team tested this system in vitro and in vivo. They identified cells from 19 genera...from different bee species. BTK can be used to introduce fluorescent markers to visualize localization ...protein. The expression of this fusion is under control of the arabinose-inducible promoter. Cells are ...showed that this method can be used for both in vitro and in vivo studies. Find distributed cell division... -
Stabilized Bacterial Promoters: Constant Gene Expression at any Copy Number
TypeBlog Post...eliminate fluctuations due to copy number by introducing genes of interest into the chromosome. But this...input signal that both positively and negatively controls the output. In this case, plasmid copy number ...gene increases its expression. However, if you introduce negative regulation by using a promoter that is.... placed a trans-acting RepA protein under the control of IPTG. Because RepA is a plasmid replication ...Segall-Shapiro et al. placed the genes under the control of a constitutive promoter and then moved them ...decreased. But when the genes were placed under the control of a stabilized promoter, deoxychromoviridans titers...the joys of a p-value < 0.05, having such fine control of gene expression is useful for many metabolic... -
Human Germline Editing Using CRISPR
TypeBlog Post...autosomal dominant mutation in MYBPC3 that leads to hypertrophic cardiomyopathy. An adult male with a heterozygous...containing Cas9 and two different gRNAs, and electroporated them with an ssODN repair template in induced...wild-type copies of MYBPC3 (versus 47.4% of untreated controls.) 27.6% of embryos carried indels at the mutation...blastocyst stage at similar rates to untreated controls. Ma et al. performed sequencing of 23 potential... conducted whole genome sequencing in selected control and CRISPR-Cas9 injected embryos. In all cases,...challenging for homozygous mutations. Moreover, introducing new DNA seems impossible with current tools, ...applicable in many situations. In the case of hypertrophic cardiomyopathy and other genetic disorders, ... -
Mouse Modeling, Part 1: Genetically Engineered Mice
TypeBlog Post...All three can introduce multiple base pair deletions, but CRISPR/Cas9 can also introduce point mutations...homologous recombination. A targeting vector is electroporated into embryonic stem cells and this will insert...joining, the newly inserted gene may have errors introduced to the nucleotide sequence during the DNA repair... in more detail in part 2 of this blog series) controls the cell types in which the conditional recombination...engineered mouse model allows gene expression to be controlled through a drug or small molecule that regulates..., Cre is fused to the ligand binding domain of estrogen receptor alpha (Esr1). Mice are fed or injected... -
Hot Plasmids and Viral Preps - January 2021
TypeBlog Post... A fast blue-light inducible Cre for precise control of bacterial gene expression By Meghan Rego Recombinases...recombinases to manipulate genomes, scientists can control expression of their genes of interest. While recombinases...their activity can be fine-tuned and precisely controlled through the use of optogenetics. Optogenetic ...authors demonstrate that CRISPR-Casɸ is active in vitro as well as in human and plant cells. Casɸ...assay for mammalian cells. It's based on the introduction & resolution of two DSBs in a fluorescent reporter...serotype AAV5. Get the channelrhodopsin here Astrocyte specific tight affinity glutamate sensor from ...from the Sanford Boye lab with enhanced retinal tropism. Find the upcoming serotypes here ... -
Plasmids 101: Terminators and PolyA signals
TypeBlog Post... affinity terminator may be desired for multi-cistronic constructs where high termination efficiency is...structure. It is thought that poly(A)s are used to control the cellular concentration of regulatory RNAs and... and may additionally act as a quality control mechanism to rid the cell of mis-folded RNAs. Eukaryotic...virus 40 late polyadenylation signal by using in vitro analyses. Molecular and Cellular Biology. 1992. ...Ther. 2008. PMID: 18627247 Zufferey R, Donello JE, Trono D, Hope TJ. Woodchuck Hepatitis Virus Posttranscriptional...Enhances Expression of Transgenes Delivered by Retroviral Vectors. Journal of Virology. 1999. PubMed PMID...Resources on the Addgene Blog Learn how the Promoter Controls Gene Expression Learn about New Cloning Techniques... -
The Materials Science of Optogenetics Experiments
TypeBlog Post...stimulation itself, the output of the laser must be controlled. As discussed above, each opsin variant has slightly...the A.M.P.I Master-9 Pulse Stimulator, which can control output of several lasers simultaneously, can be.... Pulse generation (TTL pulse) is a standard electronics protocol not specific to lasers or optogenetics...powerful alternatives to the Master-9 that only control one or two lasers are also available. Optimal stimulation...loss of laser power. More recently, wirelessly-controlled optogenetic implants have been reported by several...References 1. Gutierrez DV, et al. Optogenetic control of motor coordination by Gi/o protein-coupled vertebrate... Kim TI, et al. Injectable, cellular-scale optoelectronics with applications for wireless optogenetics... -
How-to: 5 Steps to a Great Panel Discussion
TypeBlog Post...do not let the panelists introduce themselves. I do a 1-2 minute introduction. If you chose good panelists...and will play a different role so her ability to control the event is what is important. Choose 4 panelists...logistics To make a really lively discussion, I strongly suggest asking the panelists not to use any slides...it (lapel mics are best). The moderator takes control It is the moderator's job to prevent anyone from...talking, so they will easily take 5 minutes to introduce themselves and, voila, 1/2 of your time is gone...publicity. Good panels do not waste time on long introductions. The moderator asks questions, calling on 1-... -
Special Delivery: Fluorophore Targeting for FRET Studies
TypeBlog Post...needed and when is it not? What are the proper controls needed to pressure-test your FRET assay to make...pyrrolysyl-tRNA synthetase Mammalian Cells pCMV-DnpK dinitrophenyl hapten Mammalian Cells pANAP AnapRS Mammalian...commercially available as Lumio Green and Lumio Red from Invitrogen (now ThermoFisher Scientific). These reagents...molecular distances (see Table). However, proper control experiments are needed to establish the dynamic...These experiments include producing a positive control construct where the donor and the acceptor fluorophore... each other on the same protein and a negative control experiment conducted on donor-only labeled protein...biarsenical− tetracysteine motif determined by NMR spectroscopy." Journal of the American Chemical Society 131.13... -
Pooled Library Amplifications
TypeBlog Post... of plasmids, they are generally electroporated into electrocompetent cells to ensure the highest possible...chemical transformations is less than that of electroporation, but an advantage is that chemical transformations...protocol, the size of the cuvettes your lab’s electroporator uses, etc. The DNA amount can be anywhere from...DNA in 100 μL of cells over four individual electroporations. The specifics of this can be based on the...5,000,000 30 bp At least 200 ng Liquid Electroporation Protocol (DOCX, 15.8 KB) Barcode SPLINTR... CRISPR Preparing Pooled Libraries NGS Quality Control for Pooled Libraries Resources on Addgene.org Addgene's... -
Expanded Access to Rabies Plasmids
TypeBlog Post...SARS-COV-1 plasmids. Export control license process An export control license, once approved, allows...repository, including rabies plasmids, are export-controlled materials in the USA, where Addgene is located...applicable research project when purchasing export-controlled materials. Addgene will then apply for the license... Due to recent regulation changes, an export control license for rabies materials may be required for...application process. More information about export control licenses is available through the US Bureau of ... -
Isolating Genomic Regions of Interest with the CRISPR System
TypeBlog Post... they then confirmed by PCR. Subsequent mass spectroscopy studies allowed for the identification of proteins...Fujii Lab generated a transgenic mouse line and retroviral expression system for using this approach in ...analyzed, the Fujii lab also developed another "in vitro" form. In this form, the CRISPR complex, consisting...biotinylated gRNA, were successfully used in this "in vitro" form. Any tag system can be used to isolate genomic...expressed can cause facioscapulohumeral muscular dystrophy (FSHD), a disease for which there is currently... isolation of DNA fragments and chromatin by in vitro enCh IP technology using recombinant CRISPR ribonucleoproteins...as an RNA-guided platform for sequence-specific control of gene expression." Cell 152.5 (2013): 1173-1183... -
Antibodies 101: Producing Recombinant Antibodies
TypeBlog Post...Using a spectrophotometer is among the faster methods of quantification. Many spectrophotometers have an... you have multiple contaminating bands or a few strong ones, consider increasing the number of washes ... period of two weeks. After this time, quality control assays showed that the majority of antibodies are...references More resources on the Addgene blog Introduction to Antibodies Plasmid-based Recombinant Antibodies...Protein aggregation - Mechanisms, detection, and control. Int J Pharm. 2018 Oct 25;550(1-2):251-268. doi.../j.cocis.2014.10.002. Randolph TW, Schiltz E, Sederstrom D, Steinmann D, Mozziconacci O, Schöneich C, ... -
New Viral Vectors - Spring 2025
TypeBlog Post... channelrhodopsin in the retrograde serotype, and a dTomato under the control of the E6 regulatory element...pAAV-CAG-emiRFP670 AAV1 Control Kiryl Piatkevich New viral tool pAAV-S5E6-dTom-nlsdTom AAV1 Control Jordane Dimidschstein...Wilson New serotype AAVrg = AAV retrograde (also called AAV2-retro) Looking for more viral vectors? ... -
Deciphering the Mysteries of Behavior with Viral Vectors
TypeBlog Post...for this task. However, most lesioning methods destroy areas larger than intended and may unintentionally...to the neuronal networks involved in directly controlling muscle activity and coordinating movement, several...optogenetics to support these existing findings by controlling neurons in the mPFC with light. Activation of...inhibited by fear/anxiety. On the other hand, the control group preferred staying in the dark compartment...time the animal spends in the passive mode, the stronger is the depressive component of the animal behavior... such genetic study focuses on brain derived neurotrophic factor (BDNF). BDNF is a small protein involved...the same paper, the authors used lentivirus to introduce an shRNA to downregulate expression of miR124a... -
Bacterial Toxin-antitoxin Systems as Molecular Biology Tools
TypeBlog Post... to introduce multiple genetic modifications in the same strain. MazF expression is under control of the... a GFP cassette, and introduced site-directed mutations, all without introducing unwanted selection markers...delivery vector can be integrated into the genome to introduce the genetic modification(s) contained within it...EcoRI and Bsp6I in Escherichia coli in 1995 when introduction of restriction-modification systems onto plasmids... able to monitor lacZ activity over 48 hours in vitro without antibiotic selection. In a subcutaneous ... -
Analyzing CRISPR Editing Results with ICE from Synthego
TypeBlog Post...derived from the control trace file. On the plot, the green (edited sample) and orange (control sample) lines...cells, genomic DNA from both edited and unedited (control) populations is PCR-amplified and Sanger sequenced...determined by comparing the edited trace to the control trace. In the ICE algorithm, potential editing ...summary table. You can also use your browser’s Control+F or Command+F functionality to search for a particular...disagreement between the non-edited wild type (control) and the edited sample in the region around the...difference. Traces The Traces tab shows the edited and control, non-edited Sanger traces in the region around ... -
Twenty Years of Sharing: Expanding Accessibility
TypeBlog Post...Optogenetics Guide γ-Retrovirus Guide Protocols Agarose Gel Electrophoresis Bacterial Transformation... direct shipments weren’t able to clear import control. Partnering with a distributor allowed us to share... How to Design Primers for PCR Agarose Gel Electrophoresis Inoculating Liquid Bacterial Cultures Restriction...Restriction Digest Analysis We also introduced guides — practical primers to help users get started ...we launched the Addgene YouTube channel to add a strong visual component to our educational resources. ... systems to allow for easier access to export-controlled items by streamlining permissions and paperwork...