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Showing: 141 - 160 of 796 results
  1. Plasmids 101: Protein Expression

    Type
    Blog Post
    Published
    June 7, 2018, 1:17 p.m.
    ...DNA must first be transcribed into messenger RNA (mRNA). mRNA can then be translated at the ribosome into...consists of transfecting cells with your DNA template of choice and allowing these cells to transcribe, translate...expression post-transfection. Mammalian systems can express proteins both transiently or through stable...expression vector that is then transformed into a bacterial cell. Transformed cells propagate, are induced...vitro using purified components of the transcription and translation machinery. These include ribosomes, ...proteins are then modified via an array of post-translational modifications including protein folding, formation...proteins from mRNA and the addition of post-translational modifications Learn more molecular biology ...
  2. Advancing Biology with Zebrafish: Genetic Tools for Developmental Studies and More

    Type
    Blog Post
    Published
    Aug. 13, 2019, 12:58 p.m.
    ...strategy uses a transposon called Tol2 to randomly integrate foreign DNA into the genome. Non-random integration...et al., 2019). Generating zebrafish transgenics Creating transgenic organisms by introducing foreign DNA...Danio rerio) have been used since the 1930’s in a range of biological studies, including investigations ... to produce abundant, externally fertilized, transparent progeny (Figure 2). These features give it a ...individual to maintain. Also in contrast to mice, the transparent zebrafish embryo develops outside of the mother...sequenced genome also permits “whole-genome/transcriptome” studies, in which, for example, the activity...mutants In the 1990’s, two revolutionary large-scale random mutagenesis screens produced ~1,500 zebrafish mutants...
  3. CRISPR-based Genome Editing Systems For Editing in E. coli

    Type
    Blog Post
    Published
    April 13, 2021, 1:15 p.m.
    ...in E. coli BL21(DE3) as transformants failed to grow after the transformation of pTargetF into the BL21...pTnsABC expresses the transposases TnsA, TnsB, and TnsC pQCascade expresses the transposase TniQ, the Cas proteins...expression transposases leading to increased integration frequency. (C) Increasing rounds of transfer on transposition-inducing... engineering single genome edits but the double strand breaks it introduces makes it difficult to perform...chromosomal integration using CRISPR-associated transposases” or MUCICAT. Here, we’ll describe each of these... This would result in the lack of recovered transformants. Our speculation motivated us to update the ... sequence in pEcgRNA. Next both plasmids are transformed in E. coli with the donor DNA for editing to ...
  4. CRISPR Activators: A Comparison Between dCas9-VP64, SAM, SunTag, VPR, and More!

    Type
    Blog Post
    Published
    Oct. 6, 2020, 1:15 p.m.
    ... a strong transcriptional activation domain. Guided by dCas9, VP64 recruits transcriptional machinery ...as two other potent transcriptional activators (p65 and Rta). These transcriptional activators work in ...is fused to CBP, an histone acetyltransferase domain capable of rearranging chromatin structure. This method...interest. Upon binding, CRISPRa systems recruit transcription factors to increase gene expression. CRISPRa...CRISPRa methods vary in their transcriptional activators: some methods rely on fusion proteins while others...gene regulation. This can be used to activate transcription during either initiation or elongation, depending...uses specially engineered sgRNAs to increase transcription. This is done through creating a dCas9/VP64 ...
  5. Viral Genome Sequencing - A One Stop Shop for AAV Identity and Serotype Confirmation

    Type
    Blog Post
    Published
    April 23, 2020, 1:15 p.m.
    ...previously require a preliminary double stranding step. The double stranding step was assumed to be necessary...genome is single-stranded and both TA-based ligation and tagmentation require a double-stranded template.  ...extraction, the [+] and [-] strands might naturally associate forming a double-stranded species that could be...extract is a heterogeneous mix of single-stranded and double-stranded species. While not all of the molecules...extract associate with complementary strands, enough double-stranded species exist in the mix to serve as...viral genome We hypothesized that this double stranding step might not actually be necessary. Since the...the AAV genome exists as [+] and [-] strands that are packaged at the same frequency, we reasoned that...
  6. Multicolor Animals: Using Fluorescent Proteins to Understand Single Cell Behavior

    Type
    Blog Post
    Published
    March 5, 2019, 1:08 p.m.
    ...), YFP (yellow), and membrane-tethered CFP (cyan). Brainbow 1.1 adds OFP (orange) (Livet et al., 2007)... mouse generates cells that randomly express either nuclear GFP, membrane CFP, cytoplasmic YFP, or cytoplasmic...labeling technique involves the introduction of a transgene construct containing fluorescent proteins (XFP...Because each cell can have multiple copies of the transgene that will recombine independently, cells may acquire...respectively, cells will fluoresce either red or orange until recombination occurs. Following the development...incorporates the highly photostable fluorophores mOrange2, EGFP, and mKate2 (red) to solve the problematically...non-fluorescent form of YFP as the default state of the transgene such that recombination is necessary to excise...
  7. Tips for Screening with Yeast Two Hybrid Systems

    Type
    Blog Post
    Published
    Oct. 22, 2015, 2:30 p.m.
    ...format of some transcriptional activators: that the DNA binding domain (DBD) and transcriptional activation...flurry of discovery in the field of eukaryotic transcriptional activation and cell biology. During this period... regardless of whether it interacts with a transcriptional activator (1a) or a repressor (1b). Scientists...interactions. In later years, improvements to yeast transformation protocols also helped establish the yeast two-hybrid...reporters and some that repress instead of activate transcription. The HIS3 reporter system (e.g. the Gateway-...even possible to have Y2H systems that avoid transcriptional reporters altogether; In the split-luciferase...group of prey fusions can either be generated using random genomic fragments from the organism of interest...
  8. Antibodies 101: Designing Your First Flow Panel

    Type
    Blog Post
    Published
    May 28, 2024, 1:45 p.m.
    ...cells in vitro. I transduced the cultured cells with a virus that encodes a transgenic protein for the ...having a separately expressed transduction reporter is that not every transduced cell will necessarily manage...the transgenic protein. We don't know yet how abundantly CD45 will be expressed on the transduced cells...panel to analyze transduced HEK 293T cells. Here, we looked at both the transduction efficiency and the...emission. The visible color spectrum is located in a range of wavelengths of about 380–700 nm. Photons of lower...electrons of a fluorophore, they can do so at a range of wavelengths, rather than at just one defined ...Likewise, the emitted photons also appear within a range of wavelengths. For that reason, we speak of excitation...
  9. Viral Vectors 101: AAV Serotypes and Tissue Tropism

    Type
    Blog Post
    Published
    Jan. 16, 2025, 3:42 p.m.
    ...  AAV8 AAV8 has high transduction efficiency in multiple tissues, rapid transgene expression, and can ...undergo retrograde transport, traveling up the axon to the cell body and driving transgene expression (Tervo... S. (2013). Analysis of transduction efficiency, tropism and axonal transport of AAV serotypes 1, 2, 5...vitreous. Science Translational Medicine, 5(189), 189ra76. https://doi.org/10.1126/scitranslmed.3005708 Goertsen...N-linked sialic acids1 AAV receptor2   AAV2 Heparan sulfate proteoglycan (HSPG)3 AAV receptor (not ...good choice for targeting neurons, with high transduction frequencies in the central nervous system (CNS...Asokan, et al., 2006). AAV1 has also been found to transduce skeletal muscle, cardiac, and retinal cells (Issa...
  10. Nanoblades: Tiny CRISPR Ninjas for Genome Editing Difficult Cells

    Type
    Blog Post
    Published
    Sept. 26, 2019, 12:50 p.m.
    ...delivery include plasmid transfection, RNP electroporation, and viral transduction; but these methods aren...they can then fuse with the target cell membrane, and transfer their CRISPR cargo into the zygote. As ...Repair (HDR), CRISPR activation or repression, transgenic mouse line creation, and in vivo gene editing... non-replicative. Nanoblades are produced by transfecting the following four components into 293T cells...spontaneously assemble into particles at the cell membrane. Mature Nanoblades then bud into the cell culture... can also deliver Cas9 variants, such as a transcriptional activator dCas9-VPR, if these variants are ...Rless glycoprotein (BaEVRless) had high rates of transduction for most cell types they tested. Interested ...
  11. Illuminating Epigenetics with A FRET Based Biosensor

    Type
    Blog Post
    Published
    Nov. 19, 2015, 3:30 p.m.
    ...paternal grandmothers early food supply influenced cardiovascular mortality of the female grandchildren." BMC...histone modifications, which can influence the transcription of genes by RNA polymerase II, or by the addition...methylcytosine in CpG islands makes  genes less transcriptionally active. The role of epigenetics in studying...to play a large role in a variety of diseases, ranging from cancer, to diabetes, to congenital disorders...isolated population in Sweden found that paternal grandfathers who had experienced famine before their adolescence...adolescence passed on a heritable trait to their grandsons that decreased their likelihood of death from ...of death from diabetes. Conversely, paternal grandmothers who experienced famine while still in their ...
  12. Multiple Plasmids at a Low Price: Kits from Addgene

    Type
    Blog Post
    Published
    Sept. 14, 2016, 2:30 p.m.
    ...genes from a single transcript, or if you want to prevent read-thru transcription from resulting in the...developing a general translation initiation sequence known as the Species-Independent Translational Sequence (SITS...institution, you can order plasmids covering a wide range of fields from Addgene. What you might not know ...extensive sequences used for cloning into the final translated products. Negative selection markers built into...multidrug efflux pump by novel and powerful pyranopyridine derivatives." Proceedings of the National Academy...3509-3514. Tikhonova, Elena B., et al. "A transcription blocker isolated from a designed repeat protein...of which you can clone your gene of interest. Translation of the standardized leader peptide prevents secondary...
  13. Degrading DNA with Cascade-Cas3

    Type
    Blog Post
    Published
    Feb. 11, 2025, 2:15 p.m.
    ...non-target strand. The helicase domain is then activated, and Cas3 begins unraveling the double-stranded DNA ...cleaving the ssDNA strands. In this way, Cas3 eats away at both the non-target and target strands by making cuts...every so often. Cutting both strands ensures that there isn’t a template strand left behind that the cell... regions on the non-target strand. Occasional cleaving of the target strand is not as well understood ...bypassed by leaving out Cas3 — a tactic some CRISPR transposase systems utilize with type I-F Cascades. ... section for details). The newly formed single-stranded DNA (ssDNA) is then pulled through Cas3. After...implies — after nicking, Cas3 reels in the non-target strand of DNA much like a fisherman would reel in a big...
  14. CrispyCrunch: High-throughput Design and Analysis of CRISPR+HDR Experiments

    Type
    Blog Post
    Published
    Feb. 7, 2019, 2:16 p.m.
    ...summary per batch. Ranking guides for HDR in-depth In other tools, guides are ranked by specificity of ...genome by eye. We came up with a ranking formula that does just this: Rank = (compressed CFD score) * (gaussian...interactions (e.g., scores >80) are transformed to 100. This transformation (illustrated in the graph below...CFD scores (which range between 0 and 100) are then converted to a weight (which ranges between 0 and 1)...These values (ranging from -40 bp to 40 bp) are also converted to a weight (which ranges between 0 and...employs biological best practices. For example, it ranks guides by CFD score, and it mutates HDR donor templates...cut-to-insert distance) This gives each guide a score ranging between 0 and 1. The cutting frequency determination...
  15. Truncated gRNAs for Regulating Gene Expression

    Type
    Blog Post
    Published
    Jan. 10, 2017, 3:37 p.m.
    ...which cleaves one strand of DNA upon binding the protospacer. The resulting double strand break (DSB) stimulates...two catalytic domains, HNH and RuvC, cleave DNA strands complementary and non-complementary to the gRNA... binds the target site, but does not cut either strand of DNA. Traditional Cas9 regulators In addition... then be fused to effector domains such as transcriptional activators or repressors. These fusion proteins...loci within a single cell. One might imagine transfecting cells with both the nuclease-positive and nuclease-null...Consequently, fewer genetic tools for targeted transcriptional and epigenetic regulation have been validated...inexpensively generate a potent Cas9-based transcriptional regulator without making any functional changes...
  16. Adenoviral Delivery of CRISPR/Cas9 Aims to Expand Genome Editing to Primary Cells

    Type
    Blog Post
    Published
    Dec. 10, 2020, 1 p.m.
    ...AdV-mediated transduction of gRNA:Cas9 ribonucleoprotein complexes into transformed and non-transformed cells...(right) are transduced to target cells. Within target cells, Cas9 machinery is transiently expressed and... viruses. Adenoviruses are non-enveloped double-strand DNA viruses with a genome of around 36 kb in size...left), a fragment is deleted from two homologous strands of DNA through error-prone non-homologous end joining...other viral vectors, AdVs can provide a large transgene packaging capacity. For instance, with a packaging...disruption frequencies in the various cell types ranged from 18% to 65% (Maggio et al., 2014). An alternative... to provide a DNA template to repair the double strand break via homology directed repair and you would...
  17. When is a Monomer not a Monomer? The Top Three Ways Your Favorite Fluorescent Protein Oligomerizes in Cells

    Type
    Blog Post
    Published
    April 19, 2016, 2:30 p.m.
    ...contacts that bring apposing membranes together and can wrap the membranes into stacked structures including...dimerization.   1. Transmembrane fluorescent protein fusions Transmembrane proteins, i.e. receptors...receptors and transporters, are integrated into lipid bilayers. Fusion of an FP to a transmembrane protein significantly...Green Fluorescent Protein (GFP/EGFP) for a transcriptional reporter or as a general cytoplasmic label ...making FPs monomeric, yet many investigators remain ignorant of FP dimerization. Equally problematic, several...they cannot tumble in 720°, i.e. they are on a membrane or in an organelle, then their effective concentration...dimerizing fluorescent proteins is illustrated. 1) Membrane proteins fused to FPs that dimerize can form dynamic...
  18. Hot Plasmids - December 2019 - CRISPR pooled library, LipoGlo, CRISPRa, and Voltage Imaging Tools

    Type
    Blog Post
    Published
    Dec. 10, 2019, 1:58 p.m.
    ...activation of transcription in bacteria by co-opting σ54-based transcription. Transcription from σ54 promoters...enables researchers to maximize the chance of transducing a only a single gRNA per cell. The viral DNA ...genomic DNA. However, some cell types are poorly transduced by lentivirus, and thus screening with available...not possible. Primary murine T cells cannot be transduced by lentivirus and have been difficult to manipulate...Yusa Lab. This retroviral library was used to transduce T helper type 2 (Th2) cells from mice that constitutively...screening of cells that are refractory to lentiviral transduction, now enabling forward genetic screens in cells...they develop rapidly, they are small, and their transparency allows for whole organism imaging. They created...
  19. Hot Plasmids Spring 2024

    Type
    Blog Post
    Published
    May 23, 2024, 1:15 p.m.
    ...RNA polymerase III transcript, the sgRNAs were encoded on the lentiviral minus strand in the 3’ LTR. These...HeLa cells transduced with SARS-CoV-2 nucleocapsid protein (Plasmid #141391-LV [+N]) or membrane protein ...high microglia transduction efficiency for the indicated ssAAV5s. Figure adapted from Serrano et al. 2023... with tRNAs, which are cleaved out of the RNA transcript by endogenous processing enzymes (Figure 1). ...including modifications to the Cas9 or reverse transcriptase enzymes, inhibition of host cell proteins, and...microglia are notoriously resistant to viral transduction. Through in vivo screening of human promoters...scAAV vectors have limited size compared to single-strand AAV (ssAAV). To maintain the packaging capacity...
  20. New Tools Enable CRISPRa for Neuroscience Applications

    Type
    Blog Post
    Published
    July 2, 2019, 12:51 p.m.
    ...engineered combinations of transcriptional activators to induce gene transcription at genomic sites targeted...p65-HSF1 transcriptional activator to each genome-bound dCas9 (see Figure 1a for the transgenic construct...different untranslated or coding regions. Typically, each gene isoform has a distinct transcriptional start...investigation. Co-transduction of primary rat neurons with dCas9-VPR and sgRNAs targeting either transcript variant...activation (CRISPRa) tools for neuroscience, including transgenic mice, neuron-optimized viral vectors, and high-throughput...with the development of a Suntag-p65-HSF1 (SPH) transgenic mouse (Zhou et al., 2018). This mouse expresses...CRISPRa to selectively target these different transcriptional start sites in order to better understand isoform-specific...
Showing: 141 - 160 of 796 results