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We narrowed to 842 results for: Eras

Showing: 61 - 90 of 842 results
  1. Your Lentiviral Plasmid FAQs Answered

    Type
    Blog Post
    Published
    April 23, 2014, 1:08 p.m.
    ...Second-generation vectors are likely sufficient for most experiments; however, the 3rd-generation packaging... 2nd vs. 3rd Generation Lentiviral Plasmids Q3: How can you tell 2nd- and 3rd-generation transfer vectors...considered safer. Second-generation transfer plasmids MUST be packaged with a 2nd-generation system because the... Third-generation plasmids can be packaged with either system. Please note that the generation used to...limiting the interaction between viral LTR enhancers and the transgene; such interactions can alter expression...production (3 or 4). Third-generation vectors contain gag, pol, and rev. Second-generation contains those three...and the plasmid coding for an envelope. Three generations of lentiviral packaging systems have been developed...
  2. Proximity Labeling: A Powerful Tool for Protein Complex Purification and Proteomic Mapping

    Type
    Blog Post
    Published
    Dec. 2, 2019, 2 p.m.
    ...protein-protein interactions, RNA-protein interactions, and even more recently cell-cell interactions. If you’... binary protein-protein interaction as well as identify additional interacting proteins in one simple ...RNA-protein interaction detection So far, we’ve covered ways to study protein-protein interactions, but scientists...RNA-protein interactions that can regulate multiple biological functions. RapID (RNA-protein interaction detection... mammalian cells (Milo, 2013). The number of interactions between these proteins is hard to imagine yet...yet alone study. To elucidate these interactions scientists have long used antibody based affinity purification...proximity-based labeling to better capture these interactions in a vast array of biological contexts.  Proximity...
  3. Antibodies 101: Antibody Engineering and Directed Evolution

    Type
    Blog Post
    Published
    Aug. 5, 2025, 1:15 p.m.
    ...sequences. Degenerate primers Using degenerate primers is similar to error-prone PCR. Degenerate primers ...benefits antibody-based therapeutics. Whether antibodies are used directly as therapeutic agents or serve as...the same general cyclical process (Figure 2). The differences typically come in when generating the library... 2: General process of antibody directed evolution. Created with BioRender.com.   Generating mutant...high-fidelity polymerase to ensure accuracy. In this case, you would want a low-fidelity polymerase, like Taq...antibody engineering, to improve reagents and therapeutics. What is antibody engineering (and why do we...achieve this goal, including error-prone PCR, degenerate primers, gene shuffling, and structure-guided...
  4. Starter Guide to induced Pluripotent Stem Cells (iPSCs) Part 2:  Reprogramming and Transdifferentiation

    Type
    Blog Post
    Published
    Nov. 6, 2018, 1:12 p.m.
    ...Apart from fibroblasts, human keratinocytes from hair pluck, peripheral blood cells, and renal epithelial...Efficient generation of transgene-free human induced pluripotent stem cells (iPSCs) by temperature-sensitive...Efficient and rapid generation of induced pluripotent stem cells from human keratinocytes. Nat Biotechnol,...Mukherjee. The ultimate goal in the field of regenerative medicine is to replace lost or damaged cells...cell is converted to a different cell type for regeneration and repair and situations where one process ...reverts back to a pluripotent state, which then proliferates and is redifferentiated to a different cell ...stage (iPSC formation) [2, 3]. The iPSCs then proliferate and redifferentiate to another cell type of choice...
  5. Tips for Screening with Yeast Two Hybrid Systems

    Type
    Blog Post
    Published
    Oct. 22, 2015, 2:30 p.m.
    ...molecular interactions in the cell, including protein-protein, protein-DNA and protein-RNA interactions. The...case a reporter gene (e.g. luciferase or GFP), regardless of whether it interacts with a transcriptional ... the split-luciferase system, intein-mediated splicing reconstitutes functional luciferase only when fusions... fusions of the two halves of the luciferase protein interact and enable intein splicing (5). Screening...Umezawa, Y.l. Split luciferase as an optical probe for detecting protein-protein interactions in mammalian cells...create a new system for screening protein-protein interactions. In later years, improvements to yeast transformation...the classic two hybrid system (also called the interaction trap), genes encoding proteins of interest(POI...
  6. Filming Science Videos in the Age of Social Distancing

    Type
    Blog Post
    Published
    May 20, 2021, 1:15 p.m.
    ...her shirt. She rolled several long takes, and we cut it up in post.  Test: Overall, it worked. We pulled...someone to be comfortable on camera while thinking about things like lighting, camera angle, and shot composition...and wearing their mask. But while the camera is here, the operator is in a different room.   Design... best possible videos for free. We’re a small operation, so sometimes it can be a big challenge. But ask...had a couple options. The first was to put me on camera, filming myself. While easiest from a production...protocol and can guide viewers through. I know cameras, but we needed someone else. Design: Jennifer thankfully... the office, we use a Black Magic Pocket Cinema Camera 4K. It’s wonderful and simple to use, but when ...
  7. Mesothelioma - Causes, Symptoms, and Treatment

    Type
    Blog Post
    Published
    Dec. 13, 2016, 3:30 p.m.
    ...treatments, such as surgery, radiation, and chemotherapy, immunotherapy is coming to the fore as a cutting edge...performs a heated chemotherapy wash throughout the abdominal cavity. This targeted chemotherapy approach has...susceptible to up and coming immunotherapies. The standard definition of immunotherapy is the use of drugs (or...research opportunities are being provided to immunotherapy than ever before. Although different types of...great promise in up and coming treatments like immunotherapy. Mesothelioma Mesothelioma is a terrible disease...first mesothelioma symptoms in their body. The average latency period (time from first asbestos exposure... certain other naturally occurring asbestiform minerals such as erionite, are the only scientifically ...
  8. How-to: 5 Steps to a Great Panel Discussion

    Type
    Blog Post
    Published
    Oct. 22, 2014, 1:57 p.m.
    ...best). The moderator takes control It is the moderator's job to prevent anyone from derailing the show....Choose a moderator with a backbone. It is nice to have a subject area expert, but the moderator is not ...LinkedIn profiles of all panelists to the moderator. The moderator and organizers should develop a list of... the interaction is not interesting to the audience. It is a bit of an art, but active moderation gets...effortless to the audience, but the organizers and moderator should have a well-planned approach to making ... of 4-6 pre-event interview questions. The moderator (possibly with an organizer) should set up a 30 minute...to schedule. In the pre-event interviews, the moderator should be taking good notes and discovering interesting...
  9. Site Directed Mutagenesis by PCR

    Type
    Blog Post
    Published
    Aug. 2, 2016, 2:30 p.m.
    ...you need a high-fidelity polymerase. There are many high fidelty polymerases on the market; you need one...a DNA polymerase that produces blunt-ended PCR products (e.g. Phusion, Pfu, and Vent polymerases). Note...Note that certain polymerases such as Taq generate A-overhangs (a feature used in TA-cloning). Such non-complementary...site in the coding region (preferably near the 5’-end) and that also generates 4 bp overhangs. You can then... then use the Klenow fragment of DNA polymerase I to generate blunt ends from these overhangs and ligate... analyzing the role of renaturation temperature in the polymerase chain reaction." Analytical Biochemistry...this age of CRISPR; site-directed mutagenesis generally applies to plasmids, but may also facilitate genome...
  10. Quick Guide to All Things Lentivirus

    Type
    Blog Post
    Published
    March 21, 2017, 2:30 p.m.
    ...far, with safety increasing in each generation. The 1st generation of lentiviral vectors consisted of ...third-generation lentiviral vector system offers the best safety profile in terms of RCL generation because...2nd and the 3rd generation of vectors have been shown. However, with the 3rd generation you get lower viral...-create a functional virus. Indeed, by testing several vectors and packaging cell line combinations, Miller...were produced in high-titer retroviral stocks generated by the transfer of a retrovirus into the packaging...vectors Although retroviruses are still in use, considerable efforts have been devoted to develop efficient...infect non-dividing cells. Thus three different generations of lentiviral vectors have been established so...
  11. Plasmids 101: TOPO Cloning

    Type
    Blog Post
    Published
    Oct. 27, 2016, 2:30 p.m.
    ... comes from using Taq polymerase for the amplification step since Taq polymerase leaves a single deoxyadenosine...in the pair comes from a topoisomerase I-linearized backbone. DNA topoisomerase I (depicted as a green ...covalently linked to topoisomerase. Vectors in these kits also often have the topoisomerase site inserted into...mind that Taq polymerase has an error rate of about 1 in 3,500 bases. Typically polymerases with proofreading...Topoisomerase based cloning (TOPO cloning) is a DNA cloning method that does not use restriction enzymes...technique specifically uses Vaccinia virus-isolated topoisomerase I as this enzyme recognizes the DNA sequence...cleaved 3′ DNA strand and a tyrosyl residue of topoisomerase I (1). If a 5′ hydroxyl group from a different...
  12. Viral Vectors 101: Systemic Capsids

    Type
    Blog Post
    Published
    Oct. 12, 2023, 1:15 p.m.
    ...cell type coverage in rodent PNS AAV-PHP.S effectively transduces neurons in the peripheral nervous system... definition of systemic capsids. After some consideration, we offer this definition: A systemic capsid...CNS), crossing the BBB, and those targeting the peripheral nervous system (PNS). (Capsids, if you recall...capsids are engineered, as well as highlight some considerations for their use. Then, we’ll provide information...health. While it’s always helpful to start with a literature search to see what others have done, you’ll need...- or region-specific transgene expression. (a) Several engineered capsids with unique tropisms are now...IV injections are typically administered in the lateral tail vein or retro-orbital sinus. IT injections...
  13. Targeted Mutagenesis with EvolvR

    Type
    Blog Post
    Published
    Feb. 21, 2019, 1:15 p.m.
    ...diverse libraries of genetic variants. Several methods for generating mutant libraries exist, but none provide...per nucleotide per generation vs. 10 x 10-10 mutations per nucleotide per generation of wild-type E. coli... Lab at Berkeley, provides a new approach for generating novel genetic variants in bacteria. Read on to...applications. Challenges of existing mutagenesis methods Several continuous diversification methods exist, but there...growth conditions. Expression of an error prone polymerase I (PolI3M) is capable of mutagenesis in E. Coli...with error prone PCR, EvolvR uses an error prone polymerase to introduce mutations. However, by using nCas9... Figure 1: EvolvR consists of an error-prone polymerase (PolI) that is fused to a nicking Cas9. A guide...
  14. Minigenomes - a Safe Way to Study Dangerous Viruses Like the Ebola Virus

    Type
    Blog Post
    Published
    March 17, 2016, 2:30 p.m.
    ... own RNA-dependent RNA polymerase into the infected cells. The EBOV polymerase replicates the viral genome...transcribe the reporter gene (e.g. firefly luciferase). The polymerase recognizes the gene start signal and ...viral infection), producing firefly luciferase. Firefly luciferase can readily be measured to quantify...under control of a T7 RNA polymerase promoter sequence. Thus, T7 RNA polymerase also needs to be present...single (non-viral) reporter gene (e.g. firefly luciferase or eGFP) flanked by the EBOV-specific gene start...replication and reporter gene transcription by the EBOV polymerase (reviewed in 2, 5). The minigenome is capable...nucleoprotein, NP. NP associates with the viral polymerase, which is formed by a complex of two proteins...
  15. Mouse Modeling, Part 2: Breeding and Crossing Mice

    Type
    Blog Post
    Published
    Aug. 6, 2019, 12:55 p.m.
    ...mice to generate F1 Once you’ve performed your first cross, congratulations! You’ve generated F1 mice ...at the other. 3. Breed your F1 generation Now, your goal is to generate mice that are homozygous for all...progeny from future generations. 4. Continue breeding your colony You’ll want to generate enough mice that...there are many considerations for effectively breeding your mice. Because their generation involves the ... parental generation, they are likely to stay on separate chromosomes in future generations as well, a...modifications into mouse embryos. But once you generate a growing colony of genetically engineered mice...genotype at every allele decreases. Crossing mice to generate a desired phenotype Instead, genetic engineering...
  16. Plasmids 101: Terminators and PolyA signals

    Type
    Blog Post
    Published
    March 31, 2016, 2:30 p.m.
    ...single RNA polymerase for transcription, eukaryotes have three RNA polymerases (Polymerases I, II, and...different types of RNA: Polymerase I is responsible for ribosomal RNA, Polymerase II is responsible for ...noted that each eukaryotic RNA polymerase terminates differently. Polymerase III, for example, relies on ...dependent, Polymerases I and II employ different mechanisms to terminate transcription. Polymerase I uses ...mechanism, whereas Polymerase II termination is more complex and involves two RNA polymerase-associated proteins...to express genes in a given host cell type are generally broken down into two broad categories, prokaryotic...polyadenylation vary across cell types, but polyadenylation generally serves to promote transcript longevity in eukaryotes...
  17. Deep Mutational Scanning with One Pot Saturation Mutagenesis

    Type
    Blog Post
    Published
    Feb. 22, 2017, 3:30 p.m.
    ...this. Plasmid library generation prior to one pot saturation mutagenesis Several methods can be used to...mutant strand: A mix of degenerate primers and the high-fidelity Phusion polymerase are used to introduce...interest’s function. This technique relies on the generation of a plasmid library that expresses all desired...selection. Key to this process is the ability to generate full libraries of mutant proteins. Researchers...a quick and easy technique that can be used to generate complex libraries of mutant plasmids ready for...libraries. While each of these methods works well to generate libraries, they all have inherent shortcomings...with a “sloppy” version of PCR that results in a polymerase error rate of up to 2% per nucleotide position...
  18. Fluorescent Proteins 101: GFP Fusion Proteins - Making the Right Connection

    Type
    Blog Post
    Published
    April 9, 2019, 1:13 p.m.
    ...Both components of the chimera are encoded by DNA. Since researchers can generate almost any DNA sequence...whether the chimera is still functional. Final words on fluorescent protein fusions There are several choices...proteins is relatively straightforward. However, generating a fusion while keeping all of the native properties...challenging. In this blog I discuss strategies to generate fusion proteins and highlight some aspects of ...“stickiness.” Since the fluorescent tag should operate as an inert light emitting module, any tendency...the number of binding sites per unit.  There are several ways to measure stickiness. In vitro, ultracentrifugation...in cells. In addition to measuring stickiness, several researchers have also collected data on fluorescent...
  19. Luminescent Imaging with Nano-lanterns

    Type
    Blog Post
    Published
    May 25, 2017, 2:30 p.m.
    ...Renilla luciferase variant fused to an FP; when supplied with a luciferase substrate, the luciferase transfers...synthesized diacetyl coelenterazine-h. Unlike coelenterazine-h, diacetyl coelenterazine-h does not autooxidize...the media. Cellular esterase then converts diacetyl coelenterazine-h to coelenterazine-h, producing a constant...Renilla luciferase has a low quantum yield, and when transiently expressed in cells, generates much less...excitation light source. Instead, a luciferase substrate like coelenterazine is supplied in the culture medium...Nano-lantern, a fusion of a mutagenized Renilla luciferase (RLuc8) with Venus. This luminescent technology...transfer (BRET). Photons emitted by a Renilla luciferase variant are used to excite the fused fluorescent...
  20. Technique: Probe Phage Genomes for Host Binding Proteins

    Type
    Blog Post
    Published
    Sept. 29, 2016, 2:30 p.m.
    ...diagnostic tools and therapeutics. In addition, the strategic use of whole phages as therapeutics, which is also...downstream manipulations. Phi29 polymerase is a phage-derived polymerase that can perform whole genome ...for 1 h at room temperature. After this, it is helpful to subject your membrane to several freeze/thaw cycles...around 8-12 h at room temperature as opposed to overnight at optimal growth temperature. If you’re lucky enough...however, a physical fragmentation strategy is preferable. Nebulization involves forcing DNA through a ...fragmentation, repair sheared ends with T4 DNA polymerase (to create blunt ends) and ligate into a bluntly...manipulation, amplifying phage DNA with phi29 polymerase prior to fragmentation can greatly facilitate...
  21. CRISPR 101: Homology Directed Repair

    Type
    Blog Post
    Published
    Jan. 26, 2023, 2:15 p.m.
    ...desired edit are all you need to generate a knock-in.   General considerations for designing a repair template...plasmids that liberate the targeting region from the vector. Alternatively, PCR-generated or commercially...these are generally more toxic to cells than their plasmid counterparts. Another consideration for dsDNA...CRISPR/Cas9, ZFNs, and TALENs in Generating Site-Specific Genome Alterations. Edited by Doudna J and Sontheimer...external forces such as ionizing radiation, chemotherapeutics, and ultraviolet light. In this post, we will...accurate mechanism for DSB repair. The process is generally error-free provided the DNA template used for ...modifications exist in the template DNA. There are several unique HDR mechanisms, but all templated-repair...
  22. Genome-wide Screening Using CRISPR

    Type
    Blog Post
    Published
    Aug. 18, 2015, 2:30 p.m.
    ...next-generation sequencing (E). Considerations and tips for successful screens Next-generation sequencing...concentration that is sufficient to generate lentivirus. Be sure to use next-generation sequencing to check the quality...sequence. Co-delivery of wild-type Cas9 and a gRNA generates a double-strand break in the target DNA, which...goal of a genome-wide screening experiment is to generate and screen a population of mutant cells to identify...range of potential target sequences and ease of generating gRNA-containing plasmids. CRISPR genome wide-...library with the aforementioned derivatives of Cas9. Several CRISPR libraries are publicly available through...CRISPR library that is right for you There are several factors to consider when selecting a CRISPR library...
  23. Fluorescent Proteins 101: When GFP lets you down

    Type
    Blog Post
    Published
    Aug. 23, 2018, 12:05 p.m.
    ...successfully generated several functional heterotrimeric G-alpha subunit fusions that do not tolerate N- and...proper site, although it still is worthwhile to generate several variants and check the functionality of the...widely used genetically encoded fluorescent probe. Several factors contribute to the popularity of GFP including...fluorescence microscope, and finally (iv) good toleration in fusion proteins. Since GFP is such a well-...that you may run into if you choose to use it. Several of these limitations and possible solutions are...1998). Another mutation (A206K) is necessary to generate the strictly monomeric EGFP variant, mEGFP (Zacharias..., followed by an intramolecular reaction that generates the chromophore (Tsien, 1998). Importantly, this...
  24. Antibodies 101: Single Chain Fragment Variables (scFvs)

    Type
    Blog Post
    Published
    June 3, 2021, 1:15 p.m.
    ...also allows for generations of scFvs against two antigens that are impossible to generate scFvs against ...drawback for therapeutic applications where longer retention times often increase therapeutic efficacy (...-linker-VH and VH-linker-VL configurations can generate functional scFvs; however, some individual scFvs...they can be expressed in bacteria, while mAbs generally require mammalian expression systems. scFvs are...better tissue penetration which is useful for therapeutic and imaging applications; and reduced immunogenicity... (Ahmed et al., 2012). How do you generate an scFv?  scFv sequences have traditionally been cloned by ...hybridomas, but phage display is a popular way to generate scFvs.  For phage display, a pooled library of...
  25. Plasmids 101: 5 factors to help you choose the right cloning method

    Type
    Blog Post
    Published
    Aug. 21, 2018, 12:31 p.m.
    ... containing a topoisomerase I cut site, toposisomerase I, and a taq polymerase-generated insert. When ...left by Taq perfectly anneal with the topoisomerase I generated overhangs in the backbone. Once combined...For cloning in particular, another important consideration is: The number of inserts ...as some methods...technique, you first perform a round of PCR to generate DNA fragments with 15-40 bp of homology at their...fragments are then combined with an exonuclease, a polymerase, and a DNA ligase to carry out a pooled set of...When mixed, topoisomerase I provides both the endonuclease and ligase function while 5’ adenosine overhangs...processes will require a PCR reaction or two to generate templates for the cloning process. Time spent ...
  26. Addgene's Cancer Collection Pages Connect the Research Community

    Type
    Blog Post
    Published
    Sept. 6, 2016, 2:30 p.m.
    ...cellular proliferation. We have appreciated for some time the causes of this uncontrolled proliferation, in...case of cancer, uncontrolled cell proliferation. Hence it is imperative to the health of an organism that...through several different applications such as fluorescent protein fusion studies and the generation of mutant...promising results in the laboratory, and Addgene is accelerating this research by helping to make new cancer ...normally encourage cell survival, growth and proliferation, while tumor suppressors perform the opposite...proto-oncogenes and tumor suppressors to the accelerator and brake pedal of a vehicle, respectively. In... (now an oncogene), this is analogous to the accelerator of a vehicle being stuck down. Similarly, a mutation...
  27. Lentiviral Vector Uses and Overview

    Type
    Blog Post
    Published
    May 19, 2016, 2:30 p.m.
    ...infect CD4+ cells. 3rd generation lentiviral packaging system Although the 2nd generation system is safer than... created the 3rd generation system (Figure 3), which differs from the 2nd generation in two key ways. ... vectors in cancer immunotherapy. Oldham RA, Berinstein EM, Medin JA. Immunotherapy. 2015;7(3):271-84.... and they’ve also had success in clinical gene therapy applications. Read on to learn more about the current...and tracing cells in the brain (Figure 1). 2nd generation lentiviral packaging system The graphic below...lentiviral genome was condensed to create the 2nd-generation lentiviral system (Figure 2). The HIV genes that...production: Gag (structural precursor protein), Pol (polymerase), Tat (viral transactivator for transcriptional...
  28. Custom CRISPR Screens & the Green Listed Software

    Type
    Blog Post
    Published
    July 11, 2017, 2:30 p.m.
    ...by various types of interactions with their environment. These types of interactions to a large extent ...majorly accelerate progression into clinical trials. Secondary screens  If you have generated a list of...Press run and wait for the generation of an output folder containing several files. These include: Output... dropout screen identifies genetic vulnerabilities and therapeutic targets in acute myeloid leukemia."...provided by the user. This approach is useful for several applications as will be discussed below. The software...genome CRISPR knockout screens have been used in several settings, and are fantastic tools for unbiased ...discovery. With these screens, the investigator generates a cell population where all genes are knocked ...
  29. Overcoming the Challenges of Lentiviral Production

    Type
    Blog Post
    Published
    Aug. 7, 2018, 12:31 p.m.
    ... and consequently, the generation of RCLs is greatly reduced. Third generation packaging systems further...that are required to generate RCL. To overcome the titering hurdles of third generation packaging systems...these hurdles. Talking 'bout my (lentiviral) generation The first step in delivering genes via lentivirus...is best for a particular experiment. The newer generation lentiviral packaging systems were designed to...viral elements among multiple plasmids. Second generation packaging systems use 3 plasmids; an envelope...long terminal repeat (LTR) is mutated in third generation systems such that it no longer requires the viral..., Tat. For more information on the different generations of lentiviral packaging systems please see Addgene...
  30. SARS-CoV-2/COVID-19 Detection Methods Based on CRISPR/Cas

    Type
    Blog Post
    Published
    May 5, 2020, 1:15 p.m.
    ...detected using lateral flow strips. Since the probes are tagged with streptavidin, the lateral flow strip ...like CRISPR. Figure 1: An overview of the general schematic of CRISPR/Cas based COVID-19 testing ... sample and subject to isothermal recombinase polymerase amplification (RPA) using a commercially available...Isothermal amplification is done at one constant temperature, eliminating the need for thermocyclers. This...fluorescence and this approach can be incorporated into a lateral-flow readout slip that allows rapid detection.  ...one-pot reaction system and incubated at one temperature. Two Cas12a-crRNA complexes are designed, each...reaction also contains SSB, strand displacement DNA polymerase, recombinase, and the ssDNA-FQ reporters that...
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