...and inside the cells and are thus typically used for distinguishing live from dead cells. The combination...say I am culturing HEK 293T cells in vitro. I transduced the cultured cells with a virus that encodes a...panel. Besides some background cell death constantly happening in cell culture, the transduction process... to some cell death. As a result, there is a high abundance of positively stained dead cells present and...When analyzing your cells using flow cytometry, you are typically measuring the presence or absence of...certain markers on the surface or the inside of your cells. While proteins themselves can emit intrinsic fluorescence...Another way to label proteins is through treating cells with fluorophore-conjugated antibodies that attach...

...of interest into cells. Unlike gamma-retroviruses that can only infect dividing cells, lentiviruses can...dividing and non-diving cells while retroviruses can only infect dividing cells. When choosing the appropriate...to ensure that the proper cell line is used; several common laboratory cell lines including 293 were immortalized...can infect dividing and non-dividing cells.  Addgene has an extensive collection of lentiviral plasmids...transfecting four different plasmids into the producer cells (two packaging plasmids, an envelope plasmid, and...appropriate gene delivery system, the specific target cell or tissue needs to be considered. Q2: Can I use...investing time and resources into making a stable cell line. When expressing a viral construct transiently...

...introduced the reporter into the cells, you’re ready to edit. These cells are then transfected with several... up, all successfully transfected cells will express RFP while cells containing the reporter gene that...using the RFP:GFP ratio, edited cells can be sorted from unedited cells. In an experiment that targeted...Activity. Frontiers in Cell and Developmental Biology 6: . https://doi.org/10.3389/fcell.2018.00054 Sander...CRISPR experiment was successful in your organism or cell type? You can use DNA sequencing or other molecular...histone)-GFP reporter into the genome of mammalian cells.  Figure 1: The SRIRACCHA reporter construct...simply changing the gRNA used when transfecting your cells.  A plasmid that contains Cas9. The Madison lab ...

...culture cells in the drug of interest at a lethal dose for non-manipulated cells and then assay cells which...considering either a cellular screen or a selection. A selection is a process in which only cells with the trait...selection, you might put cells into a drug-containing media in which only cells which can tolerate the ... – that is, you are not specifically looking at cells that can survive. Instead, all manipulations are...off. For a screen, you would individually treat cells with many different drugs and then perform an assay...manipulating or mutagenizing a population (typically cells or small organisms) and then assaying for a functional...For example, a drug screen may be performed on a cell line possessing a patient mutation to assess how...

...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...exactly a structure or protein is located within a cell. The Goedhart lab, Gadella lab, and collaborators...

...homodimerize in cells. To understand how well fluorescent proteins approach this ideal situation, cellular assays... quantified for individual cells, and the number of 'normal' looking cells can be counted. This assay ...living cells. Strikingly, the OSER assay reveals that tagRFP does not act as a true monomer in cells (Constantini...tolerated in some applications (e.g. labeling of cells or tracking promotor activity), but it is problematic...fluorescent proteins interact or oligomerize in cells? This question is largely unanswered. Ideally, fluorescent...proteins could properly form microtubule networks in cells. Other efforts tested whether FP fusions to connexin...present in EGFP. Constantini et al, (2012) developed a cell-based assay that does a better job of detecting ...

...yielded editing of 80–90% in human cell lines and primary cells. Although cell entry of a Cas9 ribonucleoprotein...post: Peptide-assisted genome editing for primary cells Monomeric StayGold variants AAV.CAP-Mac for systemic...antibodies Peptide-assisted genome editing for primary cells By Susanna Stroik Even with the advances in CRISPR...CRISPR technology over the past decade, primary cells remain difficult to genetically edit due to toxicity...toxicity from electroporation or poor cellular entry with other transfection methods. The Junwei Shi Lab addressed...Genome Editing (PAGE). They fused the Cas enzyme to cell-penetrating peptides and co-incubate it with an ...including in clinically-relevant lines such as CAR-T cells. Plus, this method is fast! These editing frequencies...

...scFvs and T cell receptors and are expressed on T cells to make CAR T cells. The extracellular scFv portion...Bispecific T-cell engagers (BiTE®s), bind CD3 on T cells and a tumor-specific antigen, it brings T cells to a ...recognizes an antigen of interest while the intracellular T cell receptor portion of the CAR facilitates ...scFv part of the receptor can activate T cells to kill cancer cells. scFv’s small size also allows for their... display libraries screen antibody genes from B cells of immunized animals, but it's possible to avoid...also allows for screening scFv generated from the B cell antibody genes from diseased or vaccinated humans...produce scFvs in mammalian, yeast, plant, and insect cells, they are most often expressed from a plasmid in...

...that cells are labeled with their own unique color; and 2) low levels of labeling so that a cell’s projections...tables 1 and 2, with a cell-type specific promoter or enhancer now allows for cell-type-restricted expression...this plasmid pool are injected into an animal with cell-type-specific Cre, the polyA sequence is inverted... library to infect an animal expressing Cre in a cell type of interest, a scientist can isolate DNA from...(s) of the capsid gene successfully infected the cell type of interest. Repeat rounds of infection and...capsid variants with increased ability to infect the cell type of interest, which, in the case of Chan et ...transduced a higher number of neurons overall (GFP+ cells that also stained for a neuronal marker). Check ...

...can often be used in cells that are difficult to transfect, such as primary cells. Using RNPs can also...interest. This is commonly performed by transfecting cells with a plasmid, such as PX459, which encodes Cas9...must be considered when using this method:     Cells must be amenable to transfection or viral transduction...protein in complex with a targeting gRNA, to your cells of interest. Cas9 RNPs are capable of cleaving genomic...single or multi-gene knockouts in a wide variety of cell types, gene editing using homology directed repair...difficulties with protein expression that occur in cells where common eukaryotic promoters (such as CMV or...after transfection, and are quickly cleared from the cell via protein degradation pathways. This makes Cas9...

...measure, and control molecular signals, cells, and groups of cells in order to understand their activity...Fluorescence-activated cell sorting (FACS): This is a type of flow cytometry that separates mixtures of cells into distinct...Thus, FACS can be used to separate cells expressing GFP from cells that are not. Developmental/transgenic... localization profiles, acting as a biosensor or cell marker, studying protein-protein interactions, visualizing... was non-toxic and could be expressed in living cells, enabling the study of dynamic, physiological processes...monitor gene expression from that promoter in a given cell type. This type of transcription reporting was among...biosensors has been designed to detect a variety of intracellular conditions, including ion (such as Ca2+) concentrations...

...the surface of basophils and mast cells, two types of white blood cells involved in allergic reactions. ... is important because it determines what immune cells and molecules are recruited by the antibody to help...each of these functions: Recruitment of immune cells that express receptors that recognize the Fc portion...which can initiate a cascade that helps attack extracellular pathogens.  Transportation of antibodies to ...special receptors that transport antibodies through cells and into different body compartments, such as into... during a primary immune response because all B cells begin by expressing IgM. IgM has a pentamer structure...coexpressed with IgM on the surface of most immature B cells, its function is unknown. It has a monomer structure...

...differentiate induced pluripotent stem cells (Chavez et al., 2015) into neuronal cells by activating genes that cause...drug targets by finding genes that cause cell death in cancer cell lines upon activation (Gilbert et al.,... thanks to our guest bloggers Marcelle Tuttle and Alex Chavez! Marcelle Tuttle is a medical student at...Repression and Activation. Cell 159:647–661 . https://doi.org/10.1016/j.cell.2014.09.029 Konermann S, Brigham...Genome-Scale Fitness Screens. Cell Systems 6:555-568.e7 . https://doi.org/10.1016/j.cels.2018.04.011 Polstein ...and Fluorescence Imaging. Cell 159:635–646 . https://doi.org/10.1016/j.cell.2014.09.039 Wong N, Liu W,...Clouse. This post was contributed by guest bloggers Marcelle Tuttle and Alex Chavez, researchers at the Wyss...

...dTAG molecule toxicity in new cell lines Treat parental cells (or cells expressing a control -- for example...dTAG system is versatile and can be used in both cell-based assays and mouse models. The dTAG system The...broad utility for degrading targets in different cellular compartments, and in vivo utility. dTAG molecules...of N- and C-terminal fusions and degradation in a cell line of interest prior to starting knock-in experiments...the FKBP12F36V-fusion chimera of interest. In the cell lines we have evaluated to date, we observed little...different contexts (for example, IZKF1 and IZKF3 are cell-type specific transcription factors with important...selective FKBP12F36V fusion chimera degradation. In the cell lines we have evaluated to date, we have not observed...

...strategy for bacteria to count cell divisions. The technique, called distributed cell division counting (DCDC...one bright particle that segregates into one cell during cell division. To achieve the agglomeration of ...promoter. Cells are first induced with arabinose to begin expressing the SAP-RFP fusion. Then, the cells are... new particles. With subsequent cell divisions, the fraction of cells containing the particle exponentially...plasmids to both Gram-positive and Gram-negative cells.  The Wang lab further developed a modular suite... and a desired genetic payload (ex: GFP). Thus, cells can be both sorted using FACS and isolated with ...this system in vitro and in vivo. They identified cells from 19 genera across four phyla that have taken...

...be applicable to studies of cell cycle progression, epigenetics and cellular reactions to external stimuli...Weissman JS, Qi LS, Huang B. Cell. 2013 Dec 19;155(7):1479-91. doi: 10.1016/j.cell.2013.12.001. Pubmed. Find...LS, Weissman JS, Vale RD. Cell. 2014 Oct 23;159(3):635-46. doi: 10.1016/j.cell.2014.09.039. Epub 2014 Oct...labeled Cas9 to label multiple genomic loci in live cells. While other systems can be used to label loci, ...CRISPR/Cas9’s ease of use and ability to label live cells make this system truly advantageous. This new technique...nuclear organization varies across the life of a cell, or how organization may be altered in disease states...dynamics, and how they change in response to the cell cycle or other stimuli.   To create a colorful Cas9...

...two-photon microscopy. Cell. 2022 Aug 16. pii: S0092-8674(22)00916-3. doi: 10.1016/j.cell.2022.07.013 pYtags...Calcium Indicator. Front Cell Dev Biol. 2022 Jun 29;10:880107. doi: 10.3389/fcell.2022.880107. KRaION potassium...fluorescence unit fused with TRansmembrane region-to-IntrAcellular loop linkers” (MTRIA for short), where a fluorescent...inserting a circularly-permuted GFP into an intracellular loop of various G-protein-coupled receptors....fluorescent sensor for real-time measurement of extracellular oxytocin dynamics in the brain. Nat Methods....sensor relies on a change in localization to the cell membrane and not a direct change in the fluorescent...biosensors for monitoring RTK activation by shift in cellular localization. Image adapted from Farahani et al...

... brain, robust single-cell labeling is necessary to distinguish individual cells. The Brainbow-1.0 construct... May 5. PubMed. Zebrabow: multispectral cell labeling for cell tracing and lineage analysis in zebrafish... both of Harvard’s Department of Molecular and Cellular Biology, harnessed these attributes of Cre-lox... 3.2. Brainbow labeling has also been applied to cell marking and lineage tracing in other systems, such...Brainbow highlights the trend in biology towards single-cell resolution imaging. Sanes and Lichtman endeavored...door for immunostaining analysis. To achieve even cell labeling, they generated farnesylated derivatives...fluorescent proteins, which are directly trafficked to cell membranes. Membrane trafficking of farnesylated ...

... Viruses are intracellular parasites and natural vehicles for genetic information. Therefore they make...make excellent tools for genetic engineering. There are several different viral vectors to choose from,...Virus (MoMLV, MMLV, MuLV, or MLV) or Murine Stem Cell Virus (MSCV) genomes whereas lentiviral vectors ...things) gene delivery, generating pluripotent stem cells, and developing gene therapies for monogenic diseases...vectors, their infectivity is limited to dividing cells. Find tips on using gamma-retroviral vectors in ...are able to transduce dividing and non-dividing cells. More detailed descriptions of the lentiviral elements...mechanism. Scientists can express siRNAs to direct the cellular RNAi machinery to silence target genes. This empty...

...neuroscience where specific tissues, cell types, or even subcellular regions of a neuron need to be targeted...pathways, giving rise to the same cellular responses. The cellular response set off by a DREADD depends ...disease, neuroscientists need to be able to probe cells and circuits without disrupting normal brain function...it provides a noninvasive method for manipulating cell activity, especially neuronal firing. What is chemogenetics...drugs. Once activated, chemogenetic receptors hijack cell signaling pathways and can lead to such responses...requires successfully introducing receptors to target cells. Targeted and specific delivery becomes especially...ability of agonists to successfully reach target cells while resulting in minimal off target effects. For...