...CRISPR in human cells) is a CRISPR-Cas13 based antiviral method to degrade RNA from SARS-CoV-2 sequences and...for labeling specific structures within cells. HeLa cells were transfected with plasmids encoding...protein evolution Fluorescent tools for mammalian cells Nanobody purification CRISPRi and CRISPRa system...selection in the cytosol (instead of on the yeast extracellular surface) which enables tracking of protease ...mCitrine gene. mCherry is constitutively expressed. Cells are then cultured and FACS sorted. Image from Mateo...labeling structures and compartments in mammalian cells By Angela Abitua Genetically encoded fluorescent...or specific localization of biomolecules within cells. However, sometimes these fluorescent proteins might...

...externally fertilized, transparent progeny (Figure 2). These features give it a leg up (or a fin up?) over...development. Single cell sequencing-based lineage tracing Recently, gene expression in all cells of the developing...proportions of otherwise normal cell types are produced, rather than novel, abnormal cell types. Sequencing-based...understanding how genes control biology (a fact celebrated by the Nobel prize committee). But as the field...applications. For example, specific tissues such as blood cells or neurons can be fluorescently labeled, allowing...divisions, and movements of each of the thousands of cells in the developing zebrafish embryo have been tracked...developing zebrafish embryo has been mapped using single cell RNA sequencing approaches (Harland, 2018). Several...

...rate of 10-55% - the PASTE system.     Fig. 2: Schematic of programmable gene insertion with PASTE...no detectable effect on cell viability – meaning there was no measurable cell toxicity – using Cas7-11...such as mouse embryonic stem cells and glioblastoma cells. PASTE Development and discovery The first ...observed in non-dividing cells, meaning that this system wasn’t dependent on the cell’s intrinsic machinery...turning potential into impact. In molecular and cellular biology, this happens through the development ...exclusively on this space — developing tools for cellular targeting. Lately, they’ve been working on two... shRNA and Cas13 systems in a range of mammalian cell lines. However, in those same comparisons, the AbuGoot...

...al (Nature. 1988 Jul 28;334(6180):320-5.) PubMed. 2. A segment of the 5' nontranslated region of encephalomyocarditis...them. Why Use multicistronic vectors? Detecting cells that are expressing your gene, especially if you...reporters allow you to easily screen or select for cells that are expressing your gene of interest at high...promoter, multicistronic plasmids ensure that any cells that are positive for your marker should also be...anytime you want to express multiple genes in the same cell. Although it is possible to drive co-expression ...promotes translation of the viral genome in eukaryotic cells.1,2 Since then, a variety of IRES sequences have...discovered - many from viruses, but also some from cellular mRNAs. What they all have in common is the ability...

... PMID: 25184501. PubMed Central PMCID: MC4262738. 2. Doench, John G., et al. "Optimized sgRNA design to...when trying to screen a limited number of cells like primary cells or in vivo. Recently, the labs of David... cultured cells as well as more difficult conditions such as model systems and primary cells. References...with both A375 (melanoma) and AT29 (colon cancer) cells and assessed the libraries performance via the depletion...important criterion for probing a limited number of cells. Get the Brunello CRISPRko sgRNA library as pooled...subject to an increase in dsDNA breaks that can cause cell death. Thus, CRISPR inhibition (CRISPRi) libraries...study screening for vemurafenib resistance in A375 cells. The SAM system (CRISPR/Cas9 Synergistic Activation...

...split at 175 Arabidopsis homolog of the yeast TREX-2 mRNA export complex: components and anchoring nucleoporin...measuring protein expression or localization in cells, or even single-particle tracking of the bound complex...) for use with GFP(11) Multiplexed labeling of cellular proteins with split fluorescent protein tags. ...(1-10) and GFP(11) Versatile protein tagging in cells with split fluorescent protein. Kamiyama et al. ...pairs with sfCherry2(11) Multiplexed labeling of cellular proteins with split fluorescent protein tags. ...tracking of protein-protein interactions in living cells. Shao S, Zhang H, Zeng Y, Li Y, Sun C, Sun Y. Commun...

...inhibit editing (Anzalone et al., 2019). Figure 2: Starting lengths for optimizing your pegRNA primer...editing systems by manipulating cellular determinants of editing outcomes. Cell, 184(22), 5635-5652.e29. https...Guide RNA and Target DNA. Cell, 156(5), 935–949. https://doi.org/10.1016/j.cell.2014.02.001 Yan, J., Oyler-Castrillo...type of edit, genomic context, delivery strategy, cell type, and goal of the experiment. Now, onto the ...nicking of the unedited strand and encourage the cell to use the edited strand as a template during DNA...also allows certain unintended edits to escape cellular surveillance. To limit unintended incorporation...https://doi.org/10.1016/j.cell.2021.09.018 Nelson, J. W., Randolph, P. B., Shen, S. P., Everette, K. A...

...systems utilize with type I-F Cascades. Figure 2: Cascade complex from CRISPR type I-E. Created with...unwinding steps. Molecular Cell, 70(3), 385-394.e3. https://doi.org/10.1016/j.molcel.2018.03.031 Xiao, Y., ...CRISPR Cascade. Molecular Cell, 83(5), 746-758.e5. https://doi.org/10.1016/j.molcel.2023.01.024 Morisaka, ...there isn’t a template strand left behind that the cell can use to repair. Figure 3: General overview...broad and unidirectional genome editing in human cells. Nature Communications, 10(1). https://doi.org/10.1038...CRISPR–Cas systems for genome engineering in human cells. Nature Biotechnology, 37(12), 1471–1477. https:...

...PCR tube Ice Bucket 2 μL Template DNA (10 ng-500 ng) 5 μl 10X Taq buffer with MgCl 2 1 μl dNTP mix (10 ... reagents on ice): 2 μL Template DNA (10 ng-500 ng) 5 μl 10X Taq buffer with MgCl 2 1 μl dNTP mix (10 ...normally sterile dH 2 O. To make a 100uM stock of any primer, add a number of µl of dH 2 O equal to the number...annealing temperature step-wise by 1-2°C. The rate of DNA synthesis is ~1-2 kb/min. The extension time can ...work adequately. Divalent cations such as Mg 2+ and Mn 2+ stabilize the buffer solution. These cations...(PCR). Basic PCR Program Initial Denaturation for 2 minutes at 94°C: This initiation step heats the double...target DNA strand accurately and rapidly. Repeat steps 2-4 25-30 times. Final Extension for 5 minutes at 72...

...RNAzol®, QIAzol® (for Protocol Option #2) Water-saturated Phenol 2 M Sodium Acetate pH 4 Chloroform/Isoamyl...to the Option #2 - TRIzol® Protocol section below. Homogenize or lyse tissues or cells in Solution D. ...those in -80°C. Option #2 - TRIzol® Protocol Homogenize or lyse tissues or cells in TRIzol® or a similar....5% (wt/vol) N-laurosylsarcosine (Sarkosyl) 0.1 M 2-mercaptoethanol TRIzol® or similar product such as...following sequentially to 1 mL of lysate: Add 0.1 mL of 2 M sodium acetate (pH 4.0), mix thoroughly by inversion...by hand for 10 seconds. Incubate the sample(s) for 2-3 minutes on ice and centrifuge for 15 minutes at ... D per 100 mg of cells. For cultured cells: use 1 mL of Solution D per 1 X 10 7 cells. Allow sample(s)...

...that numbers are not switched around or misread.  2. Track the container - It is just as important to ... reader and an Excel spreadsheet. Start by scanning the sample barcodes into the cells in the same order...using an electric charge to help the DNA enter the cells. Some samples require a reduced antibiotic concentration...concentration or need to be transformed into different cells than were originally requested. Most of our samples...tubes and use this ID to name the corresponding Excel sheet.3. Be specific  - When assigning a physical...storage process - from deposited DNA to transformed cells and finally to bacterial glycerol stocks that are...

...more tips on using social media as a scientist here. 2) Public engagement - Participate in science festivals...decide to start your own blog, check out these two excellent articles: On the Origin of Science Writers How...

...non-specific binding in our IHC condition.   Fig. 2: Schematic of the goldilocks antibody selection process... Innovative Neurotechnologies (BRAIN) Initiative Cell Census Network, the Wu lab will be screening over...

...out for help so you can get the support you need. 2) Prepare an agenda for every meeting Supervisors are...person that all employers are eager to hire. An excellent resource to learn more about assertiveness skills...

...purification. Workflow Timeline Day 1: Purify Day 2: Buffer exchange and concentration Note: Both steps... 7.4 1X PBS-MK buffer 100X Pluronic-F68 NaCl MgCl 2 KCl Centrifugal filter units (MWCO 100 kDa) Reagent...PBS-MK buffer Dissolve 5.84 g of NaCl, 26.3 mg of MgCl 2 and 14.91 mg of KCl in 1× PBS in a final volume of...at 4 °C. 1X PBS-MK buffer Dissolve 26.3 mg of MgCl 2 , and 14.91 mg of KCl in 1× PBS in a final volume ...(C) (formulation buffer) Add 5 mL of Buffer B and 2 mL of 5 M NaCl to 43 mL PBS Procedure Preparation ...need more time, you can alternatively centrifuge for 2 h at 200,000 x g at 18 °C. Carefully take the QuickSeal...interface of the 60% and 40% gradient (see Figure 2) with an 18 ga needle. Place the first microcentrifuge...

...GUS-staining is a very useful visual reporter (Figure 2). The GUS enzyme cleaves a substrate, which will then...roots, as functional chloroplasts and leaf specific cell types are missing in roots. The development of transgenic...transformation” usual means that neither a stable cell line or plant is regenerated from the transformed...with the gene of interest is transferred into the cells. But for C. roseus, Agrobacterium infiltration into...fused to a protein of interest to elucidate the subcellular localization of your protein of interest. Find...Intrinsic GUS-like activities in seed plants." Plant cell reports 9.1 (1990): 1-5. PubMed PMID: 24226366. ...

...Hoogsten base pairs and wobble pairs.  Figure 2: (A) The codon wheel depicts the 64 codons that encodes...mammalian cells. This was the first codon optimized membrane protein expressed in mammalian cells. In this...sequence. That means there are 61 possible tRNAs. Cells however, may not express all 61 of these tRNAs and... are also optimized for expression in mammalian cells. For example, Henry Lester’s lab optimized the C...Caenorhabditis elegans GluCl ion channel genes for mammalian cells dramatically improves expression levels. Journal...

...PMID: 18478103. PubMed Central PMCID: PMC2364656. 2. Dittmar, Kimberly A., et al. "Selective charging ...reasons include: Metabolic pressures - it takes cellular resources to produce tRNAs that recognize different...mismatched translation rates and potential effects on cell growth, even hosts producing alternative tRNAs may...inclusion bodies that will generally segregate with the cell pellet during purification procedures. Even if you...a means to fine-tune gene expression." Molecular cell 59.2 (2015): 149-161. PubMed PMID: 26186290. PubMed...

...that view (Callahan et al., 2022).     Fig. 2: Students in an MDH CURE replaced select residues ...identifying new genes required for stem and progenitor cell maintenance in planarians in Developmental Biology... his teaching style, with the former offering excellent training in improvisation and the latter making...junction complex is required for stem and progenitor cell maintenance in planarians. Developmental Biology...

...American Society for Cell Biology (ASCB) or the American Chemical Society (ACS) are just 2 examples of organizations...for the position. This post on Business Insider nicely summarizes good job fair practice. Career pages..., there is an etiquette that you should follow, nicely summarized in this post on Forbes.com, and here...

...BSL-1 and BSL-2 Labs Learn how to best protect yourself when working in BSL-1 and BSL-2 labs Watch the...Two (BSL-1 and BSL-2) Safety measures for laboratories operating at BSL-1 and BSL-2 Watch the Video! Water...Generating Stable Cell Lines with Lentivirus Genomically integrate your DNA sequence into a cell line Isolating...Isolating a Monoclonal Cell Population by Limiting Dilution Generate monoclonal cell lines from a polyclonal...polyclonal pool of stable cells AAV Production in HEK293 Cells Produce adeno-associated virus to deliver your...Extraction Without a Kit Extract RNA from tissues or cells without a commercial kit Plasmid Cloning Name Description...Transfection Introduce plasmid DNA to mammalian cells Lentivirus Production Produce lentivirus with a ...

...each transformation tube by placing the bottom 1/2 to 2/3 of the tube into a 42°C water bath for 30-60 ...depending on the competent cells you are using). Put the tubes back on ice for 2 min. Add 250-1,000 μl LB...the competent cells in your hand instead of on ice Reduce step 4 from 20 - 30 mins to 2 mins on ice before...commonly referred to as 'competent cells.' Many companies sell competent cells, which come frozen and are prepared...that came with your competent cells. Pro-Tips Commercial competent cells range significantly in their ...SOC media Competent cells DNA you'd like to transform Procedure Take competent cells out of -80°C and thaw...use electro-competent cells. Instead of relying on the heat-shock to cause the cells to take up the DNA,...

...vapors. Workflow Timeline Day 1: Antigen Coating Day 2: Blocking Day 3: Primary antibody incubation Day 4...with 96-well plates 1–10 µL single channel pipette 2–20 µL single channel pipette 20–200 µL single channel...serial dilutions of the purified antigen as follows: 2 ng/µL : Add 100 µL of 20 ng/µL stock into 900 µL PBS...microfuge tube and vortex. 1 ng/µL : Add 450 µL of 2 ng/µL stock into 450 uL PBS in a microfuge tube and...37 °C for 30 min , or overnight at 4 °C . Section 2: Block the plate Prepare the wash buffer (0.05% Tween...incubate on a microplate shaker set to 400 rpm for 2 h at room temperature or overnight at 4 °C . Section...

...- Bacterial Expression mScarlet-I3 568 592 68 4.2 2 min Monomer pmScarlet-I3_C1 - Mammalian Expression...Fluorescent Protein Resources: FRET Biosensors Subcellular localization Michael Davidson Collection Blog...University of Arizona Shaner et al. : Journal of Cell Science, Vol. 120, December 2007, pp. 4247-4260 ...

...the necessary steps to perform:      Fig. 2: Quick-stepping to a FASTA file   With our outline...mission and our own, as both address the need to accelerate science using different approaches. We were also...evolved into a single, organized pipeline and accelerated the processing of our sequencing data. However...

...HeLa cells per well. Allow the HeLa cells to grow to the desired density before labeling. Section 2: Fixing...coated coverslips HeLa cells 24-well plate 4% Paraformaldehyde 5 mg/mL 4′,6-diamidino-2-phenylindole (DAPI...Fluorescent microscope 0.5–10 µL single channel pipette 2–20 µL single channel pipette 20–200 µL single channel...of the diluted antibody to the wells and incubate 2 h at RT . Remove the primary antibody and dispose ...detect antigens in cells. Here we describe the basic steps for fixing and labeling cells in culture with ...2022 Workflow Timeline Day 1: Seed cells Day 3-4: Fix and label cells Equipment Pipette controller Pipette... Seeding cells Place a sterile poly-D-lysine coated coverslip in each well of a 24-well cell culture treated...

... Werner S, Marillonnet S. PLoS One. 2011 Feb 18;6(2):e16765. doi: 10.1371/journal.pone.0016765. PubMed...really easy to clone genes for expression in plant cells. Sylvester and I chose the 96 most useful things...

...of these issues are not particularly new. Chapter 2, “The Professional Scientist,” addresses the challenges... Aliyah Weinstein, Fabienne Furt, and Quintin Marcelino for their helpful discussion of this book....

...mL glass bottle: 4 g NaCl 4 g Tryptone 2 g Yeast Extract and dH 2 O to 400 mL Note: If your lab has pre-mixed... to do a mini-prep you will usually want to start 2 mL in a falcon tube, but for larger preps you might...might want to use as much as a liter of LB in a 2 L Erlenmeyer flask. Using a sterile pipette tip or toothpick...bacterial cell. Large plasmids usually have a low copy number (approximately one or two copies per cell) and... can be present in large numbers, 50 or more per cell and have a high copy number. High copy number plasmids...increase this to 350 - 400 rpm to obtain a higher cell density. Reference Page Top Index...

...infection of cultured cells.” Nature 339 (1989). 487–488. PubMed PMID: 2725683. 2. Miller, C.J., Kassem...Love your cells and they'll love you back A successful lentiviral infection begins with your cells, both ...both your packaging cells and your target cells. Poor tissue culture practices can lead to low titers and... promote cell growth. Overgrown cultures stimulate quiescence, the resting phase of the cell cycle; quiescent...quiescent cells do not take up nucleic acid or express transgenes as well as actively dividing cells resulting...reaching 108 cells per ml before the media becomes cloudy. Mycoplasma compete with host cells for nutrients... your producer cells with fresh medium. Daily medium exchanges help alleviate cellular stresses associated...

...approximately 2-4 million proteins per cubic micron in bacteria, yeast, and mammalian cells (Milo, 2013)...about RapID! EXCELL: Proximity labeling for the detection of cell-cell interactions EXCELL is an enzyme-mediated...enzyme-mediated proximity cell labeling strategy to detect cell-cell interactions in vivo (Ge et al., 2019...et al. "Enzyme-Mediated Intercellular Proximity Labeling for Detecting Cell–Cell Interactions." Journal...a bait protein fused to BirA* in cells and then incubate those cells with exogenous biotin. After a few...peptide (LPETG). In EXCELL, the mgSrtA variant can be displayed on the surface of a cell of interest, where...-protein interactions, and even more recently cell-cell interactions. If you’re looking to identify interactions...

...positive cells by the number of only mCherry positive cells (Martin et al., 2019). Figure 2: Editing...restoring mCherry expression. Cells can then be sorted using Fluorescence-activated cell sorting (FACS) and the...easily determined by comparing cells expressing only eGFP expression to cells expressing eGFP and mCherry...expressed in cells. mCherry is constitutively expressed to identify successfully transfected cells. C-to-T ...TREE) to purify single base edited cells without the need for single cell isolation and downstream sequencing...fluorescence and cell sorting using FACS which could limit their use across different cell types and systems...sgRNA targeting the GFPACG to the cells. As expected, only the cells that contained the cytidine base ...

...of 3,5-difluoro-4-hydroxybenzylidene-imidazolinone-2-oxime (DFHO), a fluorophore modified from DsRed. DFHO...challenging to track intracellularly, but aptamers permit the study of intracellular RNA dynamics. Aptamers...RNA aptamers are used to track cellular processes by transforming cells with plasmids encoding aptamer-tagged... been used to investigate intracellular viral DNA dynamics in neuronal cells (Nilaratanakul et al., 2017...be used to simultaneously target cellular RNA to specific intracellular locations using Cas9 and track ...and later introducing the small molecule into the cell. The fluorescence that is generated allows for qualitative...). DFHBI is membrane permeable and non toxic to cells. Because it rapidly photobleaches, DFHBI can only...

...PMCID: PMC3010411. 2. Kohli, Manu, et al. "Facile methods for generating human somatic cell gene knockouts...K562 leukemia cell line and ~8 and 9% efficiencies in T-cells and hematopoietic stem cells respectively...transient transfection of 293T cells with helpers, and used to infect recipient cells. After G418 selection, ...using AAV vectors for gene editing in mammalian cells since 1998. In that year, Russell and Hirata from...used to routinely deliver sequences of interest to cells with efficiencies of 1-40% after G418 selection ...the p53 and PTEN tumor suppressor genes in human cells (Kim et al 2008). They have also used AAV gene editing...endogenous allele of the STAG2 tumor suppressor in human cells (Kim et al, 2016). The Waldman lab has designed ...

...times are limited. Day 2: Harvest cells and purify DNA (Estimated time 3-4 hours) Cells should be harvested... recover, set up overnight growth (Estimated time 2-3 hours) Transformation should be performed at the... Tubes should contain a total of 5 mL (3 mL SOC + 2 mL transformed Endura from two separate transformations...has been absorbed by the agar. This usually takes 1-2 minutes. Critical Be careful not to rip or shred the...incubation if needed. Place 100 mL sterile LB at 4 ℃. Day 2 (morning) Before beginning, prechill at least four...pellet. The total weight of each pellet should be ~1-2 g. Pro-Tip Make sure to weigh the empty tube beforehand...electrocompetent cells (Default: 4 tubes of Endura Duos, Lucigen, 60242-1) Alternatives include Stbl4 cells or other...

...gene1 [lon] ompT gal sulA11 R(mcr-73::miniTn10--TetS)2 [dcm] R(zgb-210::Tn10--TetS) General protein expression... want to make sure your cells have first reached an appropriate density. Cells in the exponential growth...collecting dead cells, and, conversely, you cannot induce too early as there are not enough cells in the culture...host protein, using up valuable resources in the cell thus leading to slowed growth. Additionally, some...such as TB or 2XYT is optimal because of the high cell-density they support; however, minimal media supplemented...

...or other cell spreading device that fits the plate. Incubate plates at 37 ℃ for 18 hours. Day 2 Observe...individual colonies and effective selection. 150 µL of 2 mg/mL Carbenicillin plated over-agar Plate shows less...individual colonies with smaller size than the 1 mg/mL and 2 mg/mL plates and effective selection. Selection Curve...investigator to conveniently plate and select transformed cells containing plasmids differing in their resistance...bent to create an “L” shape, and then used like a cell spreader. Several other devices may be used for.... During the incubation, transform DH5α E. coli cells by heatshock with the plasmid of interest. See our...the liquid is mostly absorbed. The spreading of cells can be done in the same way as the antibiotic, using...

...indicated, the antibiotic powder can be dissolved in dH 2 0. Addgene recommends making 1000X stock solutions...daughter cells. These daughter cells contain the same genetic information as the parental cell, and are...with the host cell. Like the bacterial chromosomal DNA, plasmid DNA is replicated upon cell division, and...chemistry enable isolation and purification of cellular components, such as DNA, but practically this ...and each daughter cell receives at least one copy of the plasmid. By the 1970s the combined discoveries...are thus termed clones of the original cell. The plasmid DNA is similarly referred to as cloned DNA, and... and ideally would replicate these plasmids upon cell division in addition to their own genomic DNA. Because...

...interesting things to do, feel free to crowdsource! 2. Free food generally gets people to show up If you...picniced outside of our new office space on the nicely manicured lawn of University Park at MIT.  I’m ...

...community is active, engaged, and has great questions! 2. The r/Science subreddit is well moderated. One of...questions from the AMA - as you’ll see below, it pretty nicely displays her energetic, truthful and helpful style... training is abundant, helpful, and sometimes excellent. Finally, as I said in the AMA, it’s incredibly...topics to the Addgene blog The blog has many other excellent posts on science career topics as well. Instead...