We narrowed to 936 results for: ina
-
TypeBlog Post...break down how different contaminants impact these ratios. Protein contaminants Whether you are purifying...indicator of protein contamination, but a number of other potential contaminants alter this ratio as well...phenol in your sample. RNA contaminants DNA samples can also be contaminated with RNA (and vice-versa)....Characteristic absorption spectra for pure DNA and likely contaminants found in DNA samples. The blue lines in B-D ...B-D represent the spectra for the specified contaminant, while the grey lines in B-D represent the pure ...pure DNA spectra for comparison. Each of these contaminants will have a slightly different impact on the ...alter the overall 260 nm reading, distorting the final concentration calculation and potentially impacting...
-
Multicolor Animals: Using Fluorescent Proteins to Understand Single Cell Behavior
TypeBlog Post...protein genes, Cre recombination is required before fluorescence can occur. Cre recombinase can be used alongside...only expressed following a recombination event. Tissue-specific Cre recombination in this mouse generates...may acquire one of a variety of colors when a combination of XFP are expressed. Each cell remains the same...with Brainbow The Lichtman group developed the original iteration of this technology in 2007. Used to ...cells will fluoresce either red or orange until recombination occurs. Following the development of Brainbow...the default state of the transgene such that recombination is necessary to excise the non-fluorescent YFP...that express the construct but do not undergo recombination can be detected by immunostaining of the truncated... -
10 Basic tips for mammalian cell culture
TypeBlog Post... Keep your contaminants away While it’s likely that you’re the main source of contamination for your experiments... their original condition and can replace your working stock if it gets too old or contaminated. This ...hopefully help you keep a well organized lab and contamination free environment for successful experiments:... up to half an hour can help keep your hood contamination free, but you should keep in mind that UV light...precautions necessary to keep your cells from becoming contaminated. Wipe down everything that’ll be brought under...entering the hood is another great way to prevent contamination. This sounds rather trivial, but often solves...is in progress.Learn more about cell culture contamination in this post from the ATCC Declutter! Keep the... -
The Challenges of Cell Culture
TypeBlog Post...for authentication and contamination) and cell lines can become cross contaminated and are invariably much...still used today to test for HeLa contamination. HeLa contamination is still a problem today. It is now...cell lines suffer from contamination with HeLa being the most frequent contaminant, closely followed by ...different researchers are free of contamination and match their original description. The oldest, largest...Unreproducible results are rife. Misidentified or cross-contaminated cells have been known about since 1966 when ...the majority in those days) were in fact all contaminated with HeLa cells, the first immortalized human...wasted in basic oncological research due to contamination are in the tens or hundreds of millions, let... -
CRISPR-mediated Plant Base Editors
TypeBlog Post...machinery making an original C-G pair converted to T-A or reverted to the original C-G by base excision...invented CRISPR-base editors by tethering cytosine deaminase with Cas9 nickase (nCas9). nCas9 creates a nick...indel formation. After binding with DNA, the CBE deaminates a target cytosine (C) into a uracil (U) base...., there are no naturally known 'DNA adenosine deaminases' which would theoretically give rise to an adenine...resulted in the successful evolution of an adenosine deaminase that can act on DNA for adenine base editing. ...created a mutant library of E. coli tRNA adenosine deaminases (ecTadA), fused it with dCas9, and transformed.... The artificially evolved adenosine deaminase catalyzes the conversion of a target ‘A’ to ‘I... -
Hot Plasmids: Summer 2024
TypeBlog Post...site-specific serine recombinase. First, the prime editor installs the recombinase “landing sites,” then... MagIC-Cryo-EM for enrichment and structure determination LEA proteins protect samples during cryo-EM ...editing CHARM: A compact epigenetic silencer Recombinant antibodies for marking astrocytes MagIC-Cryo-EM...MagIC-Cryo-EM for sample enrichment and structure determination By Mike Lacy Conventional cryogenic electron ...MagIC-cryo-EM for sample enrichment and structure determination. A) Schematic of workflow. B) Detail of spacer...Funabiki, H. (2024) MagIC-Cryo-EM: Structural determination on magnetic beads for scarce macromolecules ...then the recombinase handles the installation of the donor sequence. The latest work evolves and engineers... -
Using Phosphoserine to Study Protein Phosphorylation
TypeBlog Post...phosphoserine into recombinant proteins, such as the kinase MEK1 (5). MEK1 is inactive without requisite...candidate regulatory kinase is known, it’s possible to generate non-phosphorylated recombinant protein and perform...in vitro kinase reactions. Often, however, researchers lack knowledge of the regulatory kinase, access ...access to active kinase for the reaction, or have difficulties with kinase specificity in vitro. The establishment...establishment of a system in which purified, recombinant protein could be produced with site-specific incorporation...incorporation of phosphoserine directly into recombinant proteins (5). Optimization of this system defined...create a pSer/phosphomimetic dual mutant) elevated kinase activity over 70-fold over dual phosphomimetic ... -
Light Sheet Fluorescence Microscopy
TypeBlog Post...first segments of the spinal cord showing the cortico spinal tract, CST, spinal cord and cranial nerve...Cuneate tract, dCST= dorsal cortico spinal tract, vCST= ventral cortico spinal tract, dc= decussation of the...was first pioneered by Voie and colleagues and originally named orthogonal-plane fluorescence optical sectioning...Spelman focused a laser beam into a thin sheet to illuminate a fluorescent sample and captured the reflected... lens oriented perpendicular to the plane of illumination (i.e. light sheet). This is in contrast to ...described the single-plane or selective-plane illumination microscope (SPIM). In order to improve axial...optical sectioning of a specimen is based on discriminating the out-of-focus reflected light by using a... -
Plasmids 101: Golden Gate Cloning
TypeBlog Post...sites are eliminated by digestion/ligation and do not appear in the final construct. The destination vector...Type IIS enzyme and ligase. Although the original destination vector + insert may spontaneously religate...ligated following a heat inactivation step. If your genes of interest or destination vector contain multiple...correctly, the recognition sites do not appear in the final construct, allowing for precise, scarless cloning...complementary overhangs that direct assembly of the final ligation product. As shown below, a fragment with...overhangs. Entry DNA overhangs may be present in the original plasmid (Option 1) or added using PCR-based amplification...ligation can be done in one 30-minute reaction. The destination vector and entry vector(s) are placed in a single... -
Mouse Modeling, Part 1: Genetically Engineered Mice
TypeBlog Post... or under certain stimuli. Cre recombinase catalyzes the recombination of DNA sequences located between.../c, and 129. Conversely, outbred strains were originally derived from random crosses between mice of uncharacterized...Outbred strains of mice are useful for comparing dominant and recessive traits and their impact on diseases...or into embryonic stem cells. Non-homologous recombination incorporates this DNA randomly into the mouse...knockin strains are generated via homologous recombination. A targeting vector is electroporated into embryonic... ends to the breakpoint promotes homologous recombination of the targeting vector. CRISPR/Cas9-based systems... of small molecules that promote homologous recombination or the use of long single-stranded DNA have ... -
Simplify Cloning with in vivo Assembly
TypeBlog Post...intrinsic bacterial recombination pathway, referred to as recA-independent recombination, joins together ...modifications requires multiple recombination events to assemble the final plasmid. At least 5 fragments...assembly can be achieved in vivo using a bacterial recombination pathway that is present even in common lab cloning... The pathway is ubiquitous, with successful recombination reported in all laboratory E. coli strains tested...Garcia-Nafria et al., 2016) uses the bacterial recombination pathway to allow any cloning procedure to be...strain: when asking the cell to perform multiple recombination events, all linear fragments need to get into...For simple cloning requiring just one or two recombination events, homemade competent cells of 107 CFU/... -
CRISPR 101: Multiplex Expression of gRNAs
TypeBlog Post...ligated into Cas9 or dCas9-containing destination vectors. Destination vector options include humanized wt...Originally published Jan 28, 2016 and last updated Sep 10, 2020 by Jennifer Tsang. CRISPR makes it easy...ordered assembly of multiple components into a destination vector. The first step in CRISPR/Cas9 Golden ...together to allow for ordered assembly into a destination vector that expresses Cas9. This is illustrated...drive ordered assembly into a Cas9-containing destination vector. Note: depending on which method you use...fewer than four gRNAs, you’ll clone in a polyT-termination sequence for each unused promoter. This step ...to generate all of the overhangs needed for the final ligation step. Plasmids are then digested using ... -
Hot Plasmids February 2024
TypeBlog Post...delivery By Cythina Arokiaraj (Gradinaru lab) Another useful viral tool deposited by the Gradinaru lab, AAV1...recommends these recombinant antibodies for use in western blots, though the original parent clone (M2...primate brains Endothelial-specific AAV delivery Recombinant anti-FLAG tag antibodies Peptide-assisted genome...mitochondrial membranes imaged with structured illumination microscopy in HeLa cells expressing COX8a-mStayGold... photostability and brightness compared to the original, though its maturation is even faster. Published...maintaining the bright and stable fluorescence of the original (Ivorra-Molla et al., 2023). They also named their...Hridaya Patel (Addgene co-op) Researchers in the Gradinaru lab have developed an engineered adeno-associated... -
The Effect of COVID-19 on Liu Lab Plasmid Requests From Addgene Data
TypeBlog Post...though the data is heavily dominated by the U.S. (42%), Europe (23%), and China (14%). Spikes in plasmid...instabilities in the China data, so we recommend interpreting the model results for China with more uncertainty...entered lockdown for weeks to months, pausing or terminating employment for a significant fraction of the ...encountered COVID-19 at different times. Most notably, China was affected by COVID-19 earlier than the rest of...hierarchical model: Because the U.S., Europe, and China account for over 75% of all of our plasmid orders...COVID-19 event windows as 01/15/20 -- 03/15/20 for China and 03/11/20 -- 05/19/20 (the last date in our dataset...day across regions, with Europe most impacted and China least impacted. The inferred weekend effect is, ... -
Plasmids 101: Sequence and Ligation Independent Cloning (SLIC)
TypeBlog Post...SLIC), eliminated many of LIC’s constraints by relying on the power of homologous recombination. SLIC ...reading Harnessing homologous recombination in vitro to generate recombinant DNA via SLIC. Li MZ, Elledge...only does this system not use site-specific recombination, it also doesn’t require a ligation step. Based...Based on the robust system of homologous recombination found in E. coli, SLIC is a cheap, standardized... incomplete plasmid looks like a homologous recombination intermediate to bacteria, so it can be transformed...optionally boosts efficiency with the homologous recombination protein RecA. (It’s effective with as little... branch); or by incomplete PCR, which skips the final extension step to retain products with single-stranded... -
Multiple Plasmids at a Low Price: Kits from Addgene
TypeBlog Post...of extensive sequences used for cloning into the final translated products. Negative selection markers ...expression vectors additionally contain various combinations of protein tags (His, Avi, and GFP) as well ...blocker isolated from a designed repeat protein combinatorial library by in vivo functional screen." Scientific...production of a downstream peptide, the transcription terminators in this series are just the tool you need. The...this portion of the BIOFAB Plasmid Set contain terminators of varying strengths centered within GFP/RFP ...characterized in Cambray et al., 2013. These terminators can be used to precisely tune your polycistronic... for a researcher to quickly generate N- and C-terminal epitope tag fusions to a protein of interest. ... -
A Primer on Optogenetics: Introduction and Opsin Delivery
TypeBlog Post... lambda sutures and subsequent determination of the proper coordinates of your brain region of interest...activation and the kinetics of opsin activity/inactivity. Dr. Deisseroth has also generously made many... as the vector core at the University of North Carolina) that offer his constructs. Importantly, control...open-reading frame (DIO). Upon coexpression with cre recombinase (either from a mouse line or viral co-injection...specificity dependent on the promoter of the cre recombinase while still taking advantage of the robust expression...identical for all of these surgeries. Identify coordinates through a rodent brain atlas or research papers...prior to using the virus. You may need to adjust coordinates based on your own method of identifying bregma... -
pSiM24: Simplifying Plant Genetic Engineering
TypeBlog Post...Agrobacterium binary vectors Vectors designed for use in Agrobacterium are termed binary vectors because...depositor Indu Maiti has created a new and versatile binary Ti vector for both transient and stable gene expression...and E. coli. Like plasmids used in other systems, binary vectors are cloned and prepped in E. coli. However...co-cultivation with the target plant species. Thus, binary vectors contain two origins of replication, one...transferred to the plant, similar to viral vectors’ terminal repeats. It’s a lot of information to fit into...into a single plasmid, so most first-generation binary vectors are quite large (>10 kb.) Since transformation...scientists want to transfer large genes, smaller binary vectors with a larger cloning capacity would be... -
Easi-CRISPR: Generating Knock-In and Conditional Mouse Models
TypeBlog Post... 69090 pMJ915 MBP (N terminal); 6xHis (N terminal); 2xNLS (C terminal) 47327 pET-28b-Cas9-... 6xHis (C terminal); NLS (C terminal) 62933 pET-Cas9-NLS-6xHis 6xHis (C terminal); NLS (C terminal...62934 pET-NLS-Cas9-6xHis 6xHis (C terminal); NLS (N terminal) Easi-CRISPR efficiency and delivery...marker, likely by breeding to a mouse line with a recombinase. If it turned out your chimeric mice did not ... a standard dsDNA repair template is used. The original design for creating a conditional allele, or floxed...that the T7 promoter will not be included in the final ssDNA template. Figure 2: Overview of ivTRT...stop codon! Figure 3: How to design a C-terminal insertion with Easi-CRISPR. Potential guide sequences... -
Genetically-encoded Sparse Cell Labeling - A SPARC of Innovation
TypeBlog Post...the brain of Cre-expressing mice to trigger recombination and expression of a transgene (Lin et al., 2018...with precisely truncated attP sites to control recombination of the gene construct. A predictable number ...effector or retain the stop cassette following recombination. Image from Isaacman-Beck et al., 2019. Sparse... Sparse Predictive Activity through Recombinase Competition (SPARC), a genetic tool that allows for the... downstream gene expression. attP and attB, recombination sites. These sites are target sequences of PhiC31...where the stop cassette is removed during the recombination step, the effector is expressed. In cells where...expressed and the cells are not labeled. PhiC31, a recombinase. It specifically integrates an attP site into...