Skip to main content

We narrowed to 867 results for: ell

Showing: 331 - 360 of 867 results
  1. Antibodies 101: Flow Cytometry Controls

    Type
    Blog Post
    Published
    June 6, 2024, 1:50 p.m.
    ...and beads that are unable to bind to them: like cells but with far more predictability. The beads create...The benefit of beads is that they do not require cells from your experiment, and they are non-specific....flow cytometer, you generally want your positive cells to read between 104 and 105 in order to have enough...the plot to see all of your positive and negative cells. This can be achieved by adjusting your voltage ...of your experimental samples, combine it into one well or tube, and stain it with every marker you are ...gating schematic to easily determine where your cells of interest are (B).   Using FMO controls In...markers or commonly used markers that define broader cell populations (e.g., CD4, CD8b, CD11b, CD19), are ...
  2. Plasmids 101: Screening Strategies Used in Plasmid Cloning

    Type
    Blog Post
    Published
    Sept. 15, 2020, 1:15 p.m.
    ...activity. These cells, presumably the cell you want, cannot break down X-gal and are white. Cells that don’t...screening strategy as well. In a screen, you aren’t killing off a portion of the cells like in a selection... the plasmid you’re looking for out of the many cells that don’t. One way to begin the search is by using...using selection strategies, where only cells that have gained or lost a specific gene survive (ex: antibiotic...selection. Instead, all cells survive and you will need to sort through them to find the desired clone. Do your...bacteria that have taken up this vector, but it won’t tell you whether the vector contains the gRNA insert ... plates containing X-gal allows you to identify cells that took up the vector and distinguish between ...
  3. Stabilized Bacterial Promoters: Constant Gene Expression at any Copy Number

    Type
    Blog Post
    Published
    Sept. 4, 2018, 12:53 p.m.
    ... engineer cells for specific purposes. Unfortunately, plasmid copy numbers vary within cell populations...problems. Rapidly dividing cells initiate genome replication more than once per cell division and thus, genes.... When cells are dividing rapidly, multiple rounds of replication are initiated before the cell has divided...growth rate can all impact plasmid copy number in a cell. One can attempt to eliminate fluctuations due ... pSC101 with copy numbers ranging from 3-100 per cell, a stabilized promoter buffered against the effects... to stationary phase, the number of plasmids per cell increases 4-5 fold (for pUC plasmids) or ~2 fold...fold (for p15a, R6K, and ColE2 plasmids) as cell division slows (Kittleson et al., 2011). Segall-Shapiro...
  4. Plasmids 101: CcdB - The Toxic Key to Efficient Cloning

    Type
    Blog Post
    Published
    Dec. 8, 2016, 3:30 p.m.
    ... protein (CcdA) that protects the cell against the toxic CcdB. Cells that lose ccdA through the loss of...disrupted allowing cells expressing the recombinant plasmid to propagate. Any cells that contained non-recombinant...Assembly Cloning and Gateway® cloning technologies, as well as several others. Each method is unique and relies...which is responsible for plasmid maintenance during cell division. ccdB codes for the toxic protein (CcdB...broken double stranded DNA and ultimately causing cell death. ccdA, another gene found in the ccd operon...Gateway takes advantage of the same principle that cells will not propagate while expressing the gene. Briefly...can one work with a plasmid/gene that kills the cells expressing it? The answer lies in special strains...
  5. CRISPR Meets Synthetic Biology: A Conversation with MIT’s Christopher Voigt

    Type
    Blog Post
    Published
    April 22, 2015, 2:06 p.m.
    ...through programming cells. In the context of therapeutics, if you want to program a cell to identify and ...translational activity a cell has and control how much it taxes the resources of a cell. The objective is to... to the regulatory networks within E. coli host cells. Image from Nielson and Voigt (2014). ...within the wood. There are different types of cellulose fibers, pattern, shape. All of that is controlled...and target a malignant cell, then you’d need the ability to turn on genes at different times. It requires...being used. One thing is that Cas9 is toxic. When cells carry CRISPR circuitry, it can slow their growth...combination of parts in Addgene along with the software to tell you which parts are required to get the function...
  6. Educational Planarian Tools for Teaching Developmental Biology Techniques

    Type
    Blog Post
    Published
    May 24, 2018, 1:20 p.m.
    ...stain the cells that contain this mRNA-riboprobe-antibody complex and, as a result, these cells turn blue...specific cell types or entire organs in planarians. For example, the gene Piwi labels neoblast cells and the...techniques to alter gene expression or to label specific cells, but there are too few resources to teach students... required for both WISH and RNAi experiments, as well as how to perform worm amputations. They also created... in tissue. This is useful for labeling specific cell types and for viewing how gene expression changes...modified nucleotides (for example, Digoxigenin-labelled Uracil) that will bind to complementary mRNA within...Williams, Eric J. Ross, Sofia M. C. Robb, Sarah A. Elliott, Kimberly C. Tu, Alejandro Sánchez Alvarado, The...
  7. Fluorescent Proteins 101: Introduction to FRET

    Type
    Blog Post
    Published
    June 27, 2017, 1:03 p.m.
    ...fluorescent proteins available. Fortunately, several excellent reviews have collated data from various papers... monitoring sensitized emission in living plant cells." (2013). PubMed PMID: 24194740. PubMed Central ...source of error in suboptimal or undetectable FRET, well-characterized FRET reference standards can be used... alters the FRET efficiency. Detecting certain cellular changes with an intermolecular probe is often ...Miyawaki et al., 1997), was designed to measure intracellular calcium and published in 1997. Since that time...of labs to answer sophisticated questions about cellular processes. Currently, FRET experiments can probe...concentration or activity of small molecules, detect cellular processes and signaling cascades, quantify mechanical...
  8. Viral Vectors 101: Virus Safety

    Type
    Blog Post
    Published
    June 22, 2023, 1:15 p.m.
    ...producer cell line, such as HEK-293T, production of viral particles, and transduction of a target cell line...best to be well-rested and alert the day of the procedure. Mice move much more quickly than cell cultures...become a regular part of basic biological research as well as clinical therapy. These biological tools are ...re derived from viruses that can infect people, cells, and animals. Some of these viruses are completely...best practices for handling lab-grown viruses as well as potential risks and how to minimize them. Built-in...While the virus can still enter (and thus infect) cells, this safety feature prevents the virus from replicating...replicating and spreading in non-target cells, including yourself as the researcher.   Figure 1:...
  9. CRISPR 101: Anti-CRISPR Proteins Switch Off CRISPR-Cas Systems

    Type
    Blog Post
    Published
    July 23, 2020, 1:20 p.m.
    ...Davidson AR, Maxwell KL, Doudna JA (2017) A Broad-Spectrum Inhibitor of CRISPR-Cas9. Cell 170:1224-1233...Sontheimer EJ, Maxwell KL, Davidson AR (2016) Naturally Occurring Off-Switches for CRISPR-Cas9. Cell 167:1829...concern is that the longer Cas remains active in a cell, the greater chances there are for off-target edits...Streptococcus pyogenes Cas9 (SpyCas9) is the most used and well studied CRISPR system, N. meningitidis can also ...within the first six hours. When added to human cells six hours after the introduction of Cas9 RNPs, AcrIIA4...1233.e15 . https://doi.org/10.1016/j.cell.2017.07.037 Li C, Psatha N, Gil S, Wang H, Papayannopoulou T,...CRISPR/Cas9 Toxicity in Human Hematopoietic Stem Cells. Molecular Therapy - Methods & Clinical Development...
  10. Plasmids 101: Terminators and PolyA signals

    Type
    Blog Post
    Published
    March 31, 2016, 2:30 p.m.
    ...Plasmids designed to express genes in a given host cell type are generally broken down into two broad categories...purpose and mechanism of polyadenylation vary across cell types, but polyadenylation generally serves to promote...naturally occurring terminators, such as T7 and rrnB, as well as engineered high-efficiency terminators such as... thought that poly(A)s are used to control the cellular concentration of regulatory RNAs and may additionally...additionally act as a quality control mechanism to rid the cell of mis-folded RNAs. Eukaryotic termination and polyadenylation...transcribes tRNA and other short RNAs. Although not as well studied as prokaryotic termination, the basic processes... the nuclear export and translation processes as well.   Figure 2: The conserved eukaryotic polyadenylation...
  11. Hot Plasmids: Winter 2025

    Type
    Blog Post
    Published
    March 11, 2025, 1:15 p.m.
    ... primary cells. The authors used this platform to assay dozens of GPCRs across many cell types in...biosensor platform. Cell, 187(6), 1527–1546.e25. doi: https://doi.org/10.1016/j.cell.2024.01.028. New...Prime editing (PE), initially developed in human cells, has been uniquely challenging to apply in dicotyledonous...labeling approach using these constructs in HEK 293 cells (Smith et al., 2024). They then used single-molecule...constructs for tagging the kinesins KIF5A and KIF5B as well as backbones for generating other SNAPf-, CLIPf-...CLIPf-, and CLAP-tagged proteins for mammalian cell expression. These plasmids will be useful not only for...recordings of spontaneous activity in human stem cell-derived neurons expressing ASAP5-Kv. C) Cultured...
  12. Hot Plasmids and Viral Preps - May 2021

    Type
    Blog Post
    Published
    May 18, 2021, 1:15 p.m.
    ...infects host cells through binding the human angiotensin converting enzyme 2 (ACE2) cell-surface receptor...antigenic drift.    Starr et al Cell. 2020. https://doi.org/10.1016/j.cell.2020.08.012  Starr et al Science...Library generation and sequencing. From Starr et al Cell., 2020. (B) Mapping antibody-escape mutations with... SARS-CoV-2 spike RBD is displayed on the yeast cell’s surface. The Bloom lab used the library to identify... candidates were validated by IP-MS using HEK293 cell lysate where the antigens would be in their native...immunoprecipitate the entire complex in three different cell lines. The Gräslund lab plans to continue their ...protection in yeast bioproduction pathways By Gabrielle Clouse Claudia Vickers’ lab has created a novel...
  13. Which Fluorescent Protein Should I Use?

    Type
    Blog Post
    Published
    May 20, 2014, 2:06 p.m.
    ...Fluorescent Protein (GFP), a protein from the jellyfish Aequorea Victoria. Since that discovery, the family... localization of that biomolecule inside living cells. FPs classified by the emission color (emission ... the variants blue FP (BFP), cyan FP (CFP), and yellow FP (YFP) were derived. For a breakdown of GFP, ...467 nm Cyan 474 - 492 nm Green 499 - 519 nm Yellow 524 - 538 nm Orange 559 - 572 nm Red 574 - .... Therefore, these can be used as “timers” for cellular processes following their activation. The four... longer-wavelength filters (e.g. GFP also emits yellow light). Note that some combinations of FPs can ...Guest Blogger! Gal Haimovich, PhD, is a research fellow in the lab of Prof. Robert Singer at Albert Einstein...
  14. A new platform for fast functional characterization of potentially cancerous mutations

    Type
    Blog Post
    Published
    May 7, 2019, 12:39 p.m.
    ... Ba/F3 and MCF10A cellular models. Ba/F3 and MCF10A are growth factor dependent cell lines and any mutations...attempting to characterize mutations in a pooled cell population, as mutations with strong phenotypic ...corresponding wild-type genes were constructed as well. They called this library the CTD2 FASMIC Plasmid...functional groups, based on how each one impacted cell viability (see figure). Most of the mutations were...to be “neutral,” having no significant effect on cell viability compared to a wild-type control. Approximately... the mutations, however, significantly increased cell viability, and these “activators” may be the direct...represented in this collection along with hundreds of less well-studied candidates. The possibilities are vast. ...
  15. Seeing Red: Simple GFP Photoconversion

    Type
    Blog Post
    Published
    Aug. 4, 2015, 2:30 p.m.
    ... are you’ve used a GFP derivative to conduct subcellular localization studies or make a reporter construct...shown to work in plant, Drosophila and mammalian cells, and it may find wide use in biological research...turnover rate. In many cases, however, a GFP-tagged cell line or organism has already been made, and it would...made by accident. After exciting GFP-labeled plant cells at 405 nm instead of 488 nm, Sattarzadeh et al. ...excitation at 561 nm. This imaging process worked well with the common GFP variants EGFP, mGFP4-T, and ...spontaneous conversion did not occur. Tobacco suspension cell culture with cytosol-targeted GFP. White circles...this technique may not be appropriate for high-pH cellular compartments. Sattarzadeh et al. have shown that...
  16. Course-Based Undergraduate Research Experiences (CUREs)

    Type
    Blog Post
    Published
    Feb. 9, 2023, 2:15 p.m.
    ...Funded by the NSF (with Co-PIs Jessica Bell, Lisa Gentile, Ellis Bell, and Amy Springer), this group now ...Poirier, V., Pellettieri, J. 2020. The exon junction complex is required for stem and progenitor cell maintenance...identifying new genes required for stem and progenitor cell maintenance in planarians in Developmental Biology...diversity and inclusion in STEM disciplines (Bangera & Brownell, 2014; Duboue et al., 2022), as they increase ... his teaching style, with the former offering excellent training in improvisation and the latter making...CURE trainee goes on to win a Nobel!   Jason Pellettieri is Professor and Chair of the Biology Department...References and Resources References Bangera, G., Brownell, S. 2014. Course-based undergraduate research ...
  17. Cre-ating New Methods for Site-specific Recombination in Drosophila

    Type
    Blog Post
    Published
    May 12, 2015, 1:32 p.m.
    ...functional in cultured Chinese hamster ovary (CHO) cells, as well as in cortical neurons in layer 2/3 of the ...recombination varies for different constructs and cell types. Second, Cre may induce recombination at pseudo...standard UAS/GAL4 system is toxic to proliferating cells. A Cre-estrogen receptor ligand binding domain-fusion...activity and specificity with low cross-reactivity, as well as low toxicity. FLP/FRT recombinases (from Saccharomyces...recombination efficiency. When expressed in neuronal cells, each line showed broad recombinase-dependent RFP...these recombinases were also active in mammalian cells. In experiments, B3 and KD were shown to be functional... damage induced by Cre recombinase in mammalian cells. Loonstra A, Voojis M, Beverloo HB, Al Allak B, ...
  18. In Living Color: The Skinny on In Vivo Imaging Tools

    Type
    Blog Post
    Published
    March 27, 2014, 5:14 p.m.
    ...optical labeling and tracking of proteins, organelles, and living cells in a spatiotemporal manner, which is...eight millimeters – not single cells (yet) but small clusters of cells. Looking ahead What’s next, you...fluorescent proteins to observe what’s happening inside cells for at least a couple of decades. Green is the classic... were lots of fluorescent proteins made from jellyfishes and corals, but all of them fluoresce outside... vivo. “One of the reasons we can’t localize one cell at a depth of one centimeter with fluorescence is...on the other hand, are larger than the size of a cell, so they scatter much less. As a result, ultrasound...brighter, more photostable, smaller, and less toxic to cells. They’d like to make near-infrared fluorescent proteins...
  19. Overcoming the AAV Size Limitation for CRISPR Delivery

    Type
    Blog Post
    Published
    Sept. 16, 2020, 1 p.m.
    ... Guide RNA and Target DNA. Cell 156:935–949. https://doi.org/10.1016/j.cell.2014.02.001  Ran FA, Cong ... Delivery by AAV Vectors. Cell 181:136–150 . https://doi.org/10.1016/j.cell.2020.03.023 Additional Resources...acids) displayed cleavage activity in mammalian cells. SaCas9 produced indels at a similar efficiency ...package each piece into an individual AAV. When a cell is transduced by both AAVs, the full length gene...SpCas9 which had modest editing rates in HEK-293T cells when compared to the full-length SpCas9. In 2016... DBT, Gootenberg JS, Abudayyeh OO, Franklin B, Kellner MJ, Joung J, Zhang F (2017) RNA editing with CRISPR-Cas13... allows cleavage of HBB and CCR5 genes in human cells using compact expression cassettes. Sci Rep 5: ....
  20. Finding nucleic acids with SHERLOCK and DETECTR

    Type
    Blog Post
    Published
    April 16, 2020, 1 p.m.
    ...low-frequency cancer mutations from cell-free DNA fragments as well as health-related single nucleotide...Class 2 CRISPR-Cas System. Cell 163:759–771 . https://doi.org/10.1016/j.cell.2015.09.038 Additional resources...similar types of HPV, HPV16 and HPV18, from human cells, at atomolar levels, within one hour. DETECTR thus...science.aaf5573 Broughton JP, Deng X, Yu G, Fasching CL, Servellita V, Singh J, Miao X, Streithorst JA, Granados ...10.1126/science.aam9321 Gootenberg JS, Abudayyeh OO, Kellner MJ, Joung J, Collins JJ, Zhang F (2018) Multiplexed...Gootenberg JS, Abudayyeh OO, Metsky HC, Durbin AF, Kellner MJ, Tan AL, Paul LM, Parham LA, Garcia KF, Barnes...of Diverse Class 2 CRISPR-Cas Systems. Molecular Cell 60:385–397 . https://doi.org/10.1016/j.molcel.2015.10.008...
  21. Mesothelioma - Causes, Symptoms, and Treatment

    Type
    Blog Post
    Published
    Dec. 13, 2016, 3:30 p.m.
    ...if the cell dies from injury, this protein leaks out into the cytoplasm, migrates out of the cell, and ...Keytruda) causes T-cells to more easily recognize and cause the destruction of cancer cells. Pembrolizumab...cause inflammation, which can cause mesothelial cells to mutate and ultimately form cancerous tumors.  ...resection), systemic chemotherapy to kill cancerous cells that may have spread beyond the point of origin,...diagnosed so late that these treatments do not work very well. The best option in such instances is palliative...successful in killing many (if not all) of the cancer cells that may be left behind after surgery, while being...and binds cells that can begin an immune response. This important biomarker can be used to distinguish between...
  22. CUT&RUN: An Improved Method for Studying Protein-DNA Interactions

    Type
    Blog Post
    Published
    Feb. 13, 2018, 2:51 p.m.
    ...when working with cell culture, because it is easy to harvest large quantities of cells. However, when working...numbers of cells or when a high degree of signal to noise is desired. It also provides an excellent additional... been widely applied in many model organisms and cell lines. Although ChIP-seq is a relatively simple ...typically requires a large amount of input material, cells or tissue, to produce a strong enough signal over...protein of interest. First, nuclei from tissue or cell culture are isolated using lectin-coated magnetic...the usage of a strong detergent to permeabilize cells rather than to rely on nuclei extraction. They report...technique, specifically in terms of initial steps of cell or tissue preparation.   All in all, CUT&RUN offers...
  23. Sleeping Beauty Awakens for Genome Engineering

    Type
    Blog Post
    Published
    June 30, 2015, 2 p.m.
    ...to infect and replicate in host cells, but they are susceptible to cells’ defense mechanisms. The use of... transposon; the plasmid is then degraded by the cell.4.) The transposase creates a double strand break...improve its gene insertion efficiency in primary cells. In 2009, Zsuzsanna Izsvak’s lab screened many SB...tranposase variants for hyperactivity in mammalian cells. Their efforts resulted in a new and improved SB...of antibiotic-resistance genes conducted in HeLa cells). In their Nature Genetics paper, the lab showed...allows the rapid generation of stable transgenic cell lines which can robustly express your gene-of-interest...Beauty transposons rapidly generate stable transgenic cell lines. Biotechnol J. 2015 Feb 4. doi: 10.1002/biot...
  24. Donations from Addgene to Yield Answers for Rare Disease Researchers

    Type
    Blog Post
    Published
    Sept. 15, 2015, 2:30 p.m.
    ...transformation of healthy cells into melanoma cells. They’ll combine induced pluripotent stem cell (iPS) technology...gene appears to play a role in many cell processes involving cell membrane dynamics. When they learned...still no treatment available. Aguilar is a basic cell biologist. He got interested in Lowe Syndrome initially...the gene, it piqued their interest. They obtained cells from patients with the condition to reveal some ...explore the effect of various OCRL1 mutations on cell behavior in greater detail. The goal is not just...now plan to use CRISPR-Cas9 technology to create cell lines and/or mouse models carrying different SOX10...
  25. Fluorescent Protein Travel Awards - Protein Variants, a Serotonin Sensor, and an Artificial Leaf Replica System

    Type
    Blog Post
    Published
    June 4, 2019, 1:02 p.m.
    ...non-growing cells are orange, slow growing cells are orange-green, and fast growing cells are green. A...fluorescence. Cells expressing the library are then sorted by fluorescence-activated cell sorting into ...for serotonin. According to Unger, “serotonin is a well-known but poorly studied neuromodulator, and evidence... A second colonizer, labelled with a constitutively fluorescent reporter can also be used to track how...population. Last, Bernach will simultaneously monitor cell cycle and growth rate using TIMER and an unstable...reporter under the control of promoters that control cell cycle gene expression.  Additional Resources on...
  26. Quick Guide to Working with Drosophila Part 2: Controlling Gene Expression in Flies with Gal4/UAS

    Type
    Blog Post
    Published
    July 21, 2017, 12:48 p.m.
    ... to express one gene in one cell type and another gene in a different cell type (6–8). Although it’s often...systematically study gene function with temporal control and cell-type specificity! The Gal4/UAS system At a more...the hedgehog gene can be overexpressed in several cell types by using different Gal4 drivers. It is much...much easier to mate flies to get the right cell type expression as opposed to making a new fly with hedgehog... Targeted gene expression as a means of altering cell fates and generating dominant phenotypes., Development...PubMed PMID: 15262411. 4. T. D. Southall, D. A. Elliott, A. H. Brand, The GAL4 System : A Versatile Toolkit...Neuro-Trauma during Asymptomatic Viral Infections, Cell Host Microbe 22, 48-60 (2017). PubMed PMID: 28704652...
  27. Q&A with Karen Katz and Carl Paratore, the Newest Members of the Addgene Board of Directors

    Type
    Blog Post
    Published
    Feb. 19, 2019, 1:36 p.m.
    ... shared. Can you tell me a bit about your job? Katz: I’m the Director of Intellectual Property Programs... Board of Directors. Katz is the Director of Intellectual Property Programs at Suffolk University Law ...provides interesting and unique challenges for intellectual property lawyers. While there will always be...there will always be an interest in protecting intellectual property. Figuring out that balance is, and ...Suffolk is to help create new programmatic content as well as help our students succeed whether that be academically... Karen Katz, Esq Ms. Katz is the Director of Intellectual Property Programs at Suffolk University Law ...she was on law review. She clerked for Juan R. Torruella, U.S. First Circuit Court of Appeals. She served...
  28. A Novice's Perspective on Neuroscience - SfN2017

    Type
    Blog Post
    Published
    Dec. 15, 2017, 2:07 p.m.
    ...aiming to dedifferentiate mouse brain cells into neural stem cells. I was quite unsuccesful (although I... work in sociology, behavior, and artificial intelligence (including a team that created a novel form ...game Go). In addition, there was an entire story-telling session organized by Story Collider and which featured...neuroscience trade. There were, of course, many companies selling antibodies, microscopes, and dissection tools, ...versatile means of delivering genes to many different cell types with minimal immunological effects. AAVs are... used in experiments targeting genes to specific cell types in the brain, mapping neuronal networks, and...Addgene booth to learn more about these tools and to tell us how useful the service has been for their experiments...
  29. 15 Years of Addgene: The Top 15 Plasmids

    Type
    Blog Post
    Published
    Jan. 8, 2019, 1:54 p.m.
    ...plasmid. Envelope proteins determine which types of cells a virus can infect. The VSV-G envelope protein enables... enables this virus to infect many different cell types so it is useful in a wide range of applications... The 2A-GFP allows for screening of transfected cells. Find pSpCas9(BB)-2A-GFP (PX458). lentiCRISPR v2...deliver Cas9 and your gRNA of interest into mammalian cells. This vector was the top requested plasmid of 2015... popular in genome engineering. For use in human cell lines, the Zhang lab codon-optimized SpCas9. Using...puromycin cassette that makes it less efficient in some cell lines. pSpCas9(BB)-2A-Puro (PX459) V2.0 was made...capable of inducible expression of shRNA in target cells by the addition of tetracycline/doxycycline to the...
  30. Fluorescent Proteins 101: Luciferases

    Type
    Blog Post
    Published
    July 22, 2025, 1:15 p.m.
    ...Susceptible Subcellular imaging Improving Well-established High-throughput assays Available Well-established...luciferase assays require cell lysis as the most efficient means to disrupt the cell membrane and deliver ...catalyzes a chemical reaction in its abdomen to produce yellow-green light (Figure 2). Despite the title of this...produced. A similar approach can be used to analyze cell signaling pathways or miRNA knockdown. BRET for ...advantageous properties. This approach can improve live-cell imaging by avoiding autofluorescence and phototoxicity...can permit measurements of luminescence from live cells. Luciferase variants with incompatible substrates...
Showing: 331 - 360 of 867 results