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  1. Protocols for Molecular Biology, Plasmid Cloning, and Viral Preps

    Type
    Protocol
    ...the RNAi consortium for targeting human and mouse genes. Virus Name Description Link to Video General Transfection...antibiotic resistant colonies Generating Stable Cell Lines with Lentivirus Genomically integrate your DNA sequence...Population by Limiting Dilution Generate monoclonal cell lines from a polyclonal pool of stable cells AAV Production...
  2. Fluorescence Titering Assay

    Type
    Protocol
    ... but can be adapted to a variety of target cell lines and selection markers. Note, because this protocol...Millipore TR-1003-G 1X PBS pH 7.4 without calcium or magnesium, Corning 21-040-CV (cations can affect the attachment...transduction efficiency. Titer will vary between cell lines. It is not recommended to subject lentiviral supernatants...
  3. Lentivirus Production

    Type
    Protocol
    ... can be modified for alternative packaging cell lines or transfection reagents. Once produced, lentivirus...Heat-inactivated FBS 1x PBS pH 7.4 without calcium or magnesium, Corning 21-040-CV (cations can affect the attachment... cells in a T75 flask in 15 mL DMEM Complete. Wednesday: Plate 1×10 6 cells in a T75 flask in 15 mL DMEM...
  4. Protocol - How to Run an Agarose Gel

    Type
    Protocol
    ...migrate through the gel more quickly than longer ones. Thus, you can determine the approximate length ...you can infer the size of the DNA in your sample lanes. For more details on doing diagnostic digests and...A few simple ways to increase the resolution (crispness) of your DNA bands include: a) running the gel...
  5. Coomassie Purity Stain of Recombinant Antibodies

    Type
    Protocol
    ... to the appropriate well. Pro-Tip Leaving clear lanes between samples will make quantifying the gel easier...Gels . Select Select Next Lane . Repeat for all lanes. Plot the area under the curves for the protein ...Figure 3 Select Analyze . Select Gels . Select Plot Lanes . One graph per lane will appear with peaks representing...
  6. AAV Production in HEK293 Cells

    Type
    Protocol
    ...Reagents Adherent HEK293T cells (ideally AAV-293T clones) Pro-Tip While adherent, these cells are very loosely...Fisher, 12605010) 1X PBS pH 7.4 without calcium or magnesium, Corning 21-040-CV (cations can affect the attachment... + 60 mL of 5 M Sodium Chloride + 4 mL of 1 M Magnesium Chloride Close the bottle and mix by inverting...
  7. CRISPR Library Amplification

    Type
    Protocol
    ...short region of DNA: guide RNAs targeting different genes in an organism's genome, for example. Amplification...altering the composition of the library. Bottlenecks, fitness differences, and plasmid recombination can all ...being lost from the pool and/or increasing the skewness of the pool. 8 electroporation cuvettes (BioRad...
  8. General Transfection

    Type
    Protocol
    ...This approach can be adapted for different cell lines and different transfection reagents. Workflow Timeline...cells in a 75 cm 2 flask in a volume of 15 mL. Wednesday: Plate 1x10 6 cells in a T75 flask in a volume...
  9. Immunocytochemistry

    Type
    Protocol
    ... fluorescent secondary antibody. This protocol outlines the steps for fixing and labeling HeLa cells for...and follow your institution's laboratory safety guidelines for disposing of waste in the appropriate container...
  10. Kit Free RNA Extraction

    Type
    Protocol
    ...dissociation of the nucleoprotein complexes. The effectiveness of your RNA isolation will depend on how effective...
  11. A Practical Approach to Choosing the B(right)est Fluorescent Protein

    Type
    Blog Post
    ...are (i) brightness, (ii) photostability and (iii) aggregation tendency. Brightness Brightness refers ...molecule. A higher brightness increases the detected signal and therefore high brightness is an important...how the brightness is best defined or determined. Here, we will explain how practical brightness is determined...determined and why practical brightness is a better criterion than theoretical brightness for selecting the brightest...protein. Theoretical brightness Two key properties of fluorophores that determine brightness are the extent ...number, the higher the theoretical brightness. The theoretical brightness often appears in tables with fluorescent...and the sample. Practical brightness A protein with a high intrinsic brightness that does not fold well ...
  12. Cloning Mammalian Cells with the Agarose Method

    Type
    Blog Post
    ... the Lindberg Lab we often make cell lines that overexpress genes of interest; more recently we have also...CRISPR vectors to generate cell lines with knockouts of specific genes. Many years ago, people in the ...give rise to single clones, and thus many plates must be examined for single clones and then handled. Additionally... Additionally, many cell lines, especially the endocrine cell lines we most commonly work with, require...cell clones with sterile truncated pipet tips. Indeed, an experienced operator can pick 48 clones from...individual cell clones with different expression characteristics from a population of transfected clones. The technique...number of single clones obtained (on occasion we have prepared two 48-well plates of clones) which enables...
  13. 27 Hot Plasmids from 2016

    Type
    Blog Post
    ...targeting their genes of interest to generate mAID fusions to endogenous genes. Cell lines with the appropriate...targeting a total of 20,121 genes within the human genome (the identity of the genes and target sequences can...continuous expansion of compatible backbones, promoters, and genes available to the community. If you ...identify both core and context-dependent human fitness genes, the laboratory of Jason Moffat at the University...cell models and identified ~4-5-fold more fitness-related genes than have been found in previous screens...uncharacterized genes that are conserved among apicomplexans and important for T. gondii fitness. Sixteen of...enable researchers to screen the entire genome for genes that regulate a wide variety of phenotypes, including...
  14. Custom CRISPR Screens & the Green Listed Software

    Type
    Blog Post
    ..., which genes are good candidates for being involved in the studied phenotype. For robustness of a screen...presenter then showed which genes they had generated knockout mice for (all of the genes involved as I recall...differentially expressed genes that are known drug targets, or all differentially expressed genes that code for ... if genes that you asked for were not found in the reference library. It’s not uncommon that genes have...5 guide RNAs (gRNAs) targeting each of the 1000 genes you’d like to investigate in your next CRISPR screen...CRISPR screens targeting a (long or short) list of genes provided by the user. This approach is useful for...investigator generates a cell population where all genes are knocked out at the population level, but each...
  15. Delivery Methods for Generating iPSCs

    Type
    Blog Post
    ...of insertional mutagenesis. Random integration also creates heterogeneous iPSC cell lines, which can complicate...complicate comparisons made between lines. Incomplete silencing of transgenes is a concern as well, and reactivation...reprogramming transgenes and the up-regulation of corresponding endogenous pluripotency genes. Retroviral...to insertional mutagenesis and random integration creates variation between iPSC clones. Retroviruses ...disrupt the expression of tumour suppressor genes and/or oncogenes, potentially leading to the presentation...insertional mutagenesis, the presence of a genetic scar, and incomplete silencing of transgenes. Overall,...Efficient and Stable Genome integration Insertional mutagenesis, transgene reactivation, residual expression ...
  16. Deep Dive: qPCR

    Type
    Blog Post
    ...profiles (Dwight, 2011).  Reference Genes  Choosing a set of reference genes deserves more attention than it...want to ensure that your reference genes are suitable for your cell lines and/or tissue types.  Please do...reference genes, plural. Your data will be much improved if you move to using multiple reference genes whenever... multiplex your reference genes to save on plate space. For many cell lines and tissue types, appropriate...and most machines have a protocol that automatically performs the normalization step.  Machines Most general-use...researcher defines log-linear phase Liu and Saint No Raw Data Reference and target genes can have...previously-generated validation data, be aware that different machines, samples, and treatments may affect the assay....
  17. Hassle-free 96-well Format Epitope Tagging Using Cas9 Ribonucleoprotein

    Type
    Blog Post
    ... epitope tagging of a large cohort of genes (e.g. tagging genes representing a protein super family). ...generation of clonal knock-in lines that we now use for IP and ChIP assays. Tag 96 genes at a time using Custom...knock-in for 96 different genes in a single go (Figure 3). We were able to tag >30 genes/plate in the first ...Derive clonal lines by single-cell deposition in 96-well plates: Characterize clonal lines by ICC and PCR...designed for ~250 genes, we have had about 30% tagging success, although many of these genes were expressed...be used at high throughput because numerous cell lines can be generated, each with a different tagged protein...ChIP assays. Creating epitope-tagged clonal cell lines remains a challenge as it relies on inefficient ...
  18. Cellosaurus: A Cell Line Information Database

    Type
    Blog Post
    ...community – particularly ones that help address ongoing problems, like cells lines. A 2014 study in Science...145,000 cell lines. Cellosaurus Cellosaurus seeks to identify and describe all cell lines used in research...and dog cell lines is included when available, and can be submitted via email for cell lines profiled in...Cellosaurus also identifies problematic cell lines: ones either suspected to be contaminate or easily ...as commonly misidentified lines. Browsing this feature to know if your lines may be especially vulnerable...to help you identify proximal lines you care about. If you have cell lines without a certified origin (...Science found that approximately one-third of cell lines used in scientific research are misidentified! Rigor...
  19. Advancing Biology with Zebrafish: Genetic Tools for Developmental Studies and More

    Type
    Blog Post
    ...70% of human genes have a counterpart in zebrafish. Understanding the function of these genes in fish will...Additional mutagenesis projects have since been initiated and today thousands of mutations in genes affecting...zebrafish Random mutagenesis screens provided a major toehold into understanding how genes control biology..., making them ideal for studying vertebrate embryogenesis. To illustrate some of the reasons that zebrafish... is to examine the consequences of manipulating genes. One reason for the success of zebrafish as a model...studies, in which, for example, the activity of all genes in response to an experimental treatment can be ...This can reveal previously unknown functions for genes, and lays the groundwork for understanding the gene...
  20. Plasmids 101: Colony PCR

    Type
    Blog Post
    ...   Saving clones for later culture: At this point, you will want to hang onto your clones for later use...start cultures of your positive clones. If you want to store your clones longer term, just streak the colonies...liquid cultures with the clones you pick and only mini-prep the positive ones. Regardless of which method...larger sized products for positive clones (+) compared to negative clones. Finally, orientation-specific ...identifying a few positive clones, the last step is to mini-prep these clones and submit the plasmids for...type of primer pair is also great for screening clones created with the same backbone but that contain... and back-bone specific primers. Find Empty Backbones at Addgene Each approach has advantages and drawbacks...
  21. Lambda Red: A Homologous Recombination-based Technique for Genetic Engineering

    Type
    Blog Post
    ...recombinant clones are generated.  A simple way to do this is to express lambda red genes from a plasmid...the red genes needed for recombineering, but also leads to expression of the int and xis genes which are...generation Expression of lambda red recombination genes. Electroporation of substrate DNA and outgrowth ...bacteria. Selection and confirmation of recombinant clones.    Figure 2: Overview of using Lambda...selectable DNA fragments, such as antibiotic resistance genes, as well as non-selectable DNA fragments, such as...activation Expression of Lambda Red recombination genes There are four ways to express the lambda red recombineering...exist that stably express lambda red recombineering genes due to integration of a defective lambda red phage...
  22. Technical Design of a Western Blot

    Type
    Blog Post
    ... common chemiluminescent methods for detection (though the enzymes used for chemiluminescence can be conjugated...classes of reporters: chemiluminescence enzymes and fluorescent proteins. Chemiluminescence enzymes are cheap...Direct westerns are simpler and faster than indirect ones and can be used in highly quantitative assays. On...appropriate for the target(s) and transfer method. Membranes The two membrane options are PVDF and nitrocellulose...the transfer: you’ll need to pre-wet most PVDF membranes before the transfer and allow them to dry afterwards...has higher background noise than nitrocellulose membranes. Pro tip! You can visualize proteins on a PVDF...reprobing, unless you buy specialty nitrocellulose membranes specifically developed to allow stripping. And...
  23. 22 Hot Plasmid Technologies from 2014

    Type
    Blog Post
    ...used to generate random mutagenesis libraries or to insert heterologous genes, reporters, or other markers...unprecedentedly-high brightness, bfloGFPa1, and the other with extremely-dim brightness, bfloGFPc1. The plasmids...Updated mini-transposon vector for bacterial mutagenesis or gene targeting Victor de Lorenzo's lab...this vector, called pBAM1, by conducting random mutagenesis in the soil bacterium Pseudomonas putida and ...successfully create GFP fusion proteins with a variety of genes across the genome. Although this tool was published...variety of GFPs with diversity in fluorescence brightness, intensity, excitation and emission spectra. ...-on system (pTRE-Tight-MitoTimer) to show its usefulness in cell culture to report changes in mitochondrial...
  24. Mobile-CRISPRi: Bringing CRISPRi to Diverse Bacteria

    Type
    Blog Post
    ...antibiotic resistance genes. Genes that are targets of antibiotics are often essential genes which creates a.... ICEBs1 carries the genes needed for conjugation, but can also carry cargo genes, like Mobile-CRISPRi...essential genes were less represented while bacteria containing guides targeting non-essential genes remained...parts: a plasmid expressing the Tn7 transposition genes (tnsA, tnsB, tnsC, tnsD, and tnsE), and a plasmid...interest following IPTG induction of conjugation genes and bi-parental mating. Following excision from ...components and a plasmid with the Tn7 transposition genes are transferred to a recipient bacteria strain of...colleagues used Mobile-CRISPRi to knockdown individual genes in several bacteria associated with human disease...
  25. Plasmids 101: Multicistronic Vectors

    Type
    Blog Post
    ...could replace one of the reporter genes above with your gene or genes of interest. Some of the plasmids...more of the genes replaced.  Additionally, 2A peptides could be PCR-cloned between your genes of interest...Co-expression of multiple genes is valuable in many experimental settings. To achieve this, scientists...useful almost anytime you want to express multiple genes in the same cell. Although it is possible to drive...multiple, individual expression cassettes, having the genes expressed from the same cassette is sometimes advantageous... relative expression levels between two or more genes is important. How do multicistronic vectors work...allow for the efficient translation of multiple genes from a single transcript. The two strategies most...
  26. Technologies Enabled by NanoLuc® Luciferase

    Type
    Blog Post
    ...fluorescent donor for a bioluminescent donor, making BRET probes. Here the bioluminescent donor is unaffected...Fusion Protein, codon-optimized Firefly luciferase genes (e.g., luc2), and NanoLuc® Luciferase are available...deep sea shrimp to a compact powerhouse of bioluminescence, NLuc is 100-fold brighter than our more common...NLuc is bright enough to detect endogenous tagged genes generated through CRISPR/Cas9 knock-in. Finally,...wavelengths should be used. Researchers often use bioluminescence to overcome these issues as traditional luciferases...infeasible for certain experimental setups. The brightness of NLuc has caught the attention of researchers...excites the fluor through a process known as bioluminescent resonance energy transfer (BRET). The fluor...
  27. Uncovering Ancestral Bias in CRISPR Research

    Type
    Blog Post
    ...that for approximately 40% of the identified genes, the genes were not expressed at all. This unexpected... and germline sequence variation in cancer cell lines took them down unexpected paths. Though this research...researchers do large-scale CRISPR screens in cancer cell lines, looking to uncover genetic dependencies of individual...if they could identify the ancestry of the cell lines (European, East Asian, Indigenous American, Africa...each ancestry group. Since about 90% of the cell lines used in DepMap CRISPR screens are of either European...for 994 of the Cancer Dependency Map cancer cell lines (left). Heatmap indicating the breakdown of ancestry...groups were differentially dependent on certain genes. This didn’t prove to be correct, either. However...
  28. Antibody Validation for Flow Cytometry

    Type
    Blog Post
    ...antibody’s labeling of the cell lines to the -omics data. The cell lines with higher expression of the ...approaches are commonly used to produce KO cell lines, some of which are commercially available. Various... – you’ll need to ensure that the parental cell lines of your chosen KO line are likely to express the...Correlation with RNA or Proteomic data from multiple cell lines/ types with different expression Flow cytometry ...combination with other approaches. If several cell lines express the target at different levels, it is possible...assessed through its ability to separate the cell lines based on expression of the target. In this case,...should have more antibodies labeling them; the cell lines with lower expression should have less antibodies...
  29. Evolution of Brainbow: Using Cre-lox for Multicolor Labeling of Neurons

    Type
    Blog Post
    ...directly trafficked to cell membranes. Membrane trafficking of farnesylated derivatives enables labeling...distinct patterns of recombination. In 2007, Joshua Sanes and Jeff Lichtman, both of Harvard’s Department ...Department of Molecular and Cellular Biology, harnessed these attributes of Cre-lox to create the Brainbow mouse...biology towards single-cell resolution imaging. Sanes and Lichtman endeavored to create a map of the brain... deletion, the design of Brainbow-2.1 cleverly combines Cre-mediated deletion and inversion. The Brainbow... prevent constant inversion of the construct. Sanes and Lichtman used pronuclear injection to insert...colors (see table to the right); in various reports, Sanes and Lichtman have observed from 90-160 distinct ...
  30. Illuminating Epigenetics with A FRET Based Biosensor

    Type
    Blog Post
    ...play a large role in turning genes ‘off’ and ‘on’, signaling which genes should be ‘read’ by the cellular...with the genes in the compacted region and results in a loss of gene expression. In this way, genes in compacted...the same exact genes, being improperly silenced in both cases. In both diseases, genes from both copies...Epigenetics has recently been hitting the headlines, with sotires like the potential devastation of the...dangerous DNA damage. If the way DNA is wrapped around histones changes, then gene expression can change as well...The more frequently and tightly bound DNA is to histones, the more compacted it becomes. This prevents ...modifications, which can influence the transcription of genes by RNA polymerase II, or by the addition of methyl...
  31. Common Injection Routes in Mice

    Type
    Blog Post
    ... you wait for the anesthetized mice to breathe in the liquid. Restraint: anesthesia Location: nose Gauge...Intradermal Anesthesia Between skin layers 26 < 0.05 mL Advanced Intrathecal Anesthesia Spinal cord ...Intratracheal Anesthesia Trachea 20–23 (tubing) < 0.07 mL Advanced Intranasal Anesthesia Nose n/a < 0.05...be less stressful, because the mice are under anesthesia, but they are not recommended for tumorigenic... required. Restraint: mechanical restraint or anesthesia Location: tail vein or retro-orbitally Gauge:... the muscle. Common uses include administering vaccines, pain meds, or other drugs. Identifying the proper...sciatic nerve. Mice likely experience some muscle soreness after injection, like you might after getting ...
  32. Addgene's Cancer Collection Pages Connect the Research Community

    Type
    Blog Post
    ...roles of proto-oncogenes, tumor suppressors, and their protein products. Proto-oncogenes consist of a group...specific genes involved. Downregulation of tumor suppressors and upregulation of proto-oncogenes ­­­can ... group of genes/proteins that, when expressed, normally encourage cell survival, growth and proliferation...of control. One may compare the roles of proto-oncogenes and tumor suppressors to the accelerator and brake... the health of an organism that both classes of genes function normally to maintain balance – encouraging...lining the digestive system, causing discomfort and illness. Further, depending on the specific type of cancer...-Ras, and N-Ras) encoded by a family of proto-oncogenes. Ras proteins are special because they are known...
  33. The Challenges of Cell Culture

    Type
    Blog Post
    ...mantra being “you can’t trust those whacky cell lines”. This may certainly have been a valid concern for...quality work in cell culture. The problems with cell lines Simply put, the majority of cell line problems come... for authentication and contamination) and cell lines can become cross contaminated and are invariably...Stanley Gartler reported that most of the 18 cell lines he had studied (the majority in those days) were...line. He proved this by examining whether the cell lines had isoenzymes and genetic polymorphisms specific...problem today. It is now known that nearly 500 cell lines suffer from contamination with HeLa being the most...listing all cross contaminated or misidentified cell lines. The solution Fortunately it has never been easier...
  34. Mycoplasma Contamination: Where Does It Come From and How to Prevent It

    Type
    Blog Post
    ...reusing pipettes for multiple cell lines rather than using disposable ones or reusing gloves. The serum is... technique, PCR primers specific to the 16s RNA genes of various commonly infecting mycoplasmas are used...sensitivity but low specificity (Degeling, 2012). Bioluminescence assay kits are available from different biotech...which trigger cellular mechanisms that generate luminescence. This can then be detected by a luminometer.... for cell culturing and maintenance of the cell lines. Providing such an environment for the lab facility...Wear a clean lab coat and mask while handling cell lines. Avoid discussion with other lab members, sneezing...wearing PPE. Photo by Kate Harten DeMaio. Cell lines and reagents Examine your cell line stock for mycoplasma...
  35. Viral Vectors 101: Integrase-Deficient Lentiviral Vectors

    Type
    Blog Post
    ... to insertional mutagenesis (Howe et al., 2008). 2. Transient expression of transgenes/shRNAs If you want.... Insertional mutagenesis combined with acquired somatic mutations causes leukemogenesis following gene...of research purposes, like creating stable cell lines, delivering CRISPR/Cas9 to cells for genome editing...packaging plasmid contains Gag, Pol, Rev, and Tat genes. Specifically for our knowledge here, the Pol gene...transcriptase), and IN (integrase). These viral packaging genes are required for the production of lentiviral particles...portion does not contain any of the viral packaging genes, the natural cycle of the lentiviral vector ends...process and episomal forms of non-integrating transgenes. Created with BioRender.com; adapted from Banasik...
  36. CRISPR 101: Targeting Non-Coding RNAs with CRISPR/Cas9

    Type
    Blog Post
    ...protein-coding genes thanks to systems like CRISPR/Cas9 that allow them to manipulate full genes and observe...nearby genes and its role in gene expression, though this may still unexpectedly affect nearby genes (Figure...DA, Weissman JS. Fitness effects of CRISPR/Cas9-targeting of long non-coding RNA genes. Nature biotechnology...only 2% of our genome is made of protein-coding genes, and you might be wondering what the rest of our...manipulate and study in comparison to protein-coding genes (Rinn and Chang 2012). Scientists have determined...knock-out, or permanently disable, protein-coding genes by generating insertions or deletions in the DNA...multiple gRNAs poses the risk of disrupting adjacent genes, especially those regulated by or overlapping with...
  37. Antibodies 101: Designing Your First Flow Panel

    Type
    Blog Post
    ...important to know the brightness of individual fluorophores. Table 1 describes the brightness of a few commonly...fluorophore brightness levels, these differences are much more subtle (think of brightness levels on your...there are fixable dye stains that react with free amines on and inside the cells and are thus typically ...en-us/resources/bd-spectrum-viewer.       Brightness Apart from the excitation and emission wavelengths...commonly used fluorophores. A fluorophore's brightness refers to the signal strength of the emitted photons...fluorophores have a stronger signal. Table 1: Degrees of brightness for a few commonly used fluorophores in relation...emea.bd.com/panel-design/en/flow-cytometry-fluochrome-brightness-spillover Excitation Laser Color Very Bright...
  38. Save Time with Transient Plant Leaf Transformations

    Type
    Blog Post
    ...Infection with Agrobacterium rhizogenes can be used to develop stable hairy root lines in tissue culture. This...transformation. Choose good reporter genes There are many great reporter genes available and which one you choose...process. While developing transgenic hairy root lines in tissue cultures takes half a year, and generating...transcription factor candidates and the regulation of genes in the biosynthetic pathway. Why plant scientists...interest in the plant. A common method for silencing genes Virus induced gene silencing (VIGS) is a transient...plant's post-transcriptional machinery to silence genes of interest (Unver and Budak, 2009). This method...in C. roseus. A common method for overexpressing genes In plants like Arabidopsis and tobacco, Agrobacterium...
  39. Quick Guide to Working with Drosophila Part 3: Genome Engineering in Flies

    Type
    Blog Post
    ...different fly lines. Also, if there is a chance you need to combine multiple transgenes in one fly, having...having the transgenes in different loci allows for genetic recombination so that the transgenes can be inherited...comparisons between lines expressing different variants of YFG because the transgenes are found in the same... same locus across fly lines (i.e. there won’t be positioning effects). When designing experiments where...where you want to express multiple transgenes, remember that you’ll need to integrate them all at different...accomplished with a few matings to balancer chromosome lines but is not necessary with targeted insertions (here...the white gene, which restores eye color to fly lines where the endogenous white gene is knocked out. ...
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