We narrowed to 974 results for: LAT
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TypeBlog Post...Tends to resist promoter down regulation due to methylation or deacetylation. Ubc General expression mRNA...controlled by still other regulatory factors: enhancers, boundary elements, insulators, and silencers; however...pET vectors. Very tightly regulated by the lac operators. Good for modulating gene expression through varied...Good for rapid regulation and low basal expression; however, not well-suited for modulating gene expression...repressor 10x, thus tightening regulation of lac promoter. Good for modulating gene expression through varied...and -10 region from lac. Very tight regulation. Good for modulating gene expression through varied inducer...cells and typically only in the same or closely related species from which they were derived. Similarly...
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Technique: Probe Phage Genomes for Host Binding Proteins
TypeBlog Post...and plate transformants for isolated colonies (150-200 per plate) across 20 fresh selective plates. Step...gently down onto a plate of colonies. Mark the orientation of each membrane on its plate before moving on...on. Then peel each membrane off the plate (saving the plate so you can regrow the lifted colonies overnight...therapeutics, which is also gaining a lot of new traction lately (1, 2), depends on knowledge of the structure(s... a given fragment size to be selected for by manipulating the nebulization time and pressure. Nebulization...a hose to a nitrogen gas tank with a pressure regulator. Other methods for physical shearing exist as ...working with DNA that is refractory to enzymatic manipulation, amplifying phage DNA with phi29 polymerase ... -
Illuminating Epigenetics with A FRET Based Biosensor
TypeBlog Post...disorders. A series of studies carried out on an isolated population in Sweden found that paternal grandfathers...in their DNA methylation patterns, either large increases or decreases. Hypermethylation of CpG islands... (pcDNA3-K9 histone methylation reporter) and K27 (pcDNA3-K27 histone methylation reporter) positions ...to recognise lysine 27 methylation. When tested in living cells where methylation of these sites was controlled...significantly different FRET levels between unmethylated and methylated states. Thus, this system is a reliable... transcription and inactivate them. Global hypomethylation, on the other hand, has also been implicated...immunoprecipitation, fluorescent in-situ hybridization, methylation-sensitive restriction enzyme digestion, DNA adenine... -
The Materials Science of Optogenetics Experiments
TypeBlog Post...thus individual laser stimulation is essential. In terms of the laser stimulation itself, the output of...cable is threaded through—and fixed to—an optical insulator called a ferrule (below). The fiber optic cable...significant amount of equipment, most of which is relatively cheap). Several protocols have been written outlining...the dorsal/ventral location of your region of stimulation (the z-axis bregma coordinate). Because the light...it enters tissue, placement above the site of stimulation guarantees that the majority of the opsins will...should be about 0.4-0.5mm above the site of your stimulation. The scatter effect is also an important consideration...during the entire protocol, otherwise optical stimulation will be erratic, opsin activation/inactivation... -
Rewiring Metabolic Circuitry with CRISPR RNA Scaffolds [Video]
TypeBlog Post...transcriptional regulator to modulate expression at that locus. The use of regulators allows a greater...that can recruit various transcriptional regulators (Zalatan et al. 2015). These scaffolds are stretches...promoter to modulate dCas9 expression, multiple scRNA transcriptional programs can be regulated with dCas9...University of Western Ontario. Adam summarizes Zalatan JG, et al.'s recent paper, "Engineering Complex...differentiation or metabolism. Our attempts to manipulate these cellular behaviors often fall short with...shifted in recent years toward tinkering with regulatory networks and multiplex gene control. However,...approaches are often met with the challenges of regulatory bottlenecks and their scope is limited by the... -
CRISPR 101: Homology Directed Repair
TypeBlog Post...modifications exist in the template DNA. There are several unique HDR mechanisms, but all templated-repair pathways...fix a broken relationship. Pardo B, et al. Cell Mol Life Sci (2009). PubMed. Regulation of DNA double-strand...along the way. HDR uses homologous sequence as a template for repair and is thus the more accurate mechanism...process is generally error-free provided the DNA template used for repair is identical to the original DNA...one strand of the homologous DNA donor and can template repair off the other strand; this results in the...mechanism that notably does not require a donor template and thus won’t be covered in detail here. Classical...pathway, the 3’ ends invade an intact homologous template to serve as a primer for DNA repair synthesis,... -
CRISPR Between the Genes: How to Experiment with Enhancers and Epigenomics
TypeBlog Post... region that has mono-methylated and acetylated histones, but not tri-methylated histones, functions as...denote enhancers as follows: (mono_methylation + acetylation) - tri_methylation In the next section we’ll ... me3, and ac – denoting mono-methylation, tri-methylation, and aceylation, respectively (these are chemical...sequencing to measure the relative proportion of guide RNAs (gRNAs) across the population. Recall that guide ...inclusive markers of regulatory regions in the genome, including enhancers, promoters, insulators, and more. I...It Locates ChIP-seq Proteins (for our example later, histones) ChiRP-seq RNA Hi-C DNA (genome-to-genome...tried and true method of finding enhancers by isolating genomic regions that are bound to modified proteins... -
New Tools Enable CRISPRa for Neuroscience Applications
TypeBlog Post...gene-function relationships in defined substructures of the CNS as well as individual neuronal populations. The...some unknown regulators of neuronal differentiation were enriched in the CD8+ population, as expected....neurons, forming the neuronal circuits that will later be refined through experience. However, studying...complicated by the lack of precise genetic tools for modulating gene expression in the central nervous system...using CRISPRa to target individual genes can be relatively laborious because multiple plasmids/viruses are...generated from the same gene but with different untranslated or coding regions. Typically, each gene isoform...can be targeted anywhere in the genome, it is relatively straightforward to use CRISPRa to selectively... -
Tips and Tricks for Using Golden Gate Modular Cloning (MoClo)
TypeBlog Post...original Addgene kit plate for fresh bacteria. Performing your Assemblies Calculate your volumes As you...Hurt for high-throughput minipreps in 96-well plates. Plate wisely You will likely see fewer numbers of ...competent cells in a 96-well PCR plate. Always confirm your results Congratulations! You have followed these ...multigene vector with two other independently regulated transcription units. Created with BioRender.com...Don’t dive directly into the pipetting! MoClo nomenclature and structure can be quite confusing for new...in what position do you want your gene to be in relation to the rest of the genes? And do you want it to...These overhangs are known as the common MoClo nomenclature. The overhangs are generated using type IIS ... -
Important Considerations in Optogenetics Behavioral Experiments
TypeBlog Post...know if you are actually stimulating or inhibiting the targeted neuronal population prior to behavioral testing...receive different types of stimulation may help to refine and optimize your stimulation parameters as well. ... and stimulate them for 30min to an hour and observe what happens. You never know how stimulation of a...personally interested in include: intracranial self-stimulation (ICSS) and place preference. The lab I work in... electrode and non-specifically electrically stimulating an ill-defined region of the brain. With the ...particular hole (the active hole) induces laser stimulation of the chosen brain circuit, while a nose-poke...different patterns and the animal only receives stimulation in one of the two chambers (see image below).... -
CRISPR/Cas9 FAQs Answered!
TypeBlog Post...target in the HR template, you usually would need to make mutations of the HR template to avoid this donor... HR template an issue? A8: Yes. If you have intact protospacer+PAM sequence within the HR template, it... that if a CRISPR is used to engineer a locus, isolate single cell colonies, then genotype them, it is...homologous recombination (HR) Q7: Can you summarize HR template vector design guidelines? A7: A few notes below...you should consider using ssDNA oligo as donor template, it's usually more efficient than plasmid donor...µl of 10 µM oligo stock for each well on 24-well plate, co-deliver into the cells with the Cas9/sgRNAs ...with Cas9/sgRNAs vector, for one well in 24-well plate. A good example/reference is Ran et al. (2013). ... -
An “elegans” Approach to Better CRISPR/Cas9 Editing Efficiency
TypeBlog Post...the model organisms which I use to study gene regulation during developmental processes, CRISPR/Cas9 allows...but currently requires additional experimental manipulation. In some cases, injection of Cre is required...mutation must be removed, which can be done by isolating animals with particular visible phenotypes. These...following a report that one can use linear repair templates (ie. PCR-derived dsDNA) with 30-60 basepair homology...ribonucleoprotein complex with linear DNA as repair templates which reduces time to generate edits to only four...but require variable amounts of experimental manipulation and screening. A co-selection strategy for ...be obtained in eight days. The only animals on a plate, other than the parental animal, are rescued progeny... -
Multiple Plasmids at a Low Price: Kits from Addgene
TypeBlog Post...developing a general translation initiation sequence known as the Species-Independent Translational Sequence (SITS... fuse custom PUF proteins to a translational repressor to down-regulate a gene of interest. You can generate...: 1147. Cooke, Amy, et al. "Targeted translational regulation using the PUF protein family scaffold....extensive sequences used for cloning into the final translated products. Negative selection markers built into...Tikhonova, Elena B., et al. "A transcription blocker isolated from a designed repeat protein combinatorial library...of which you can clone your gene of interest. Translation of the standardized leader peptide prevents secondary...encoding your gene of interest from affecting its translation initiation and instead makes initiation heavily... -
Plasmids 101: Screens vs. Selections
TypeBlog Post...Forward and reverse screens involve manipulating or mutagenizing a population (typically cells or small organisms...screens, there is random or unknown manipulation of the population. This is contrary to reverse screens...disease as the input population. For these experiments, the goal is to identify manipulations which either enhance...in that only survivable manipulations are assessed, rather than all manipulation events. To put it another...looking at cells that can survive. Instead, all manipulations are assessed, regardless of whether they enhance... is assessed. The two most common methods of manipulation are genetic knockout mutations and treatment...consider these questions to save yourself a headache later on. Enhancer and suppressor screens These types ... -
Hot Plasmids: Spring 2025
TypeBlog Post...TurboCas, the Ali Shilatifard Lab was able to identify both new and known regulators at the FOS gene promoter...nearby proteins with biotin. The biotinylated proteins can then be isolated and identified with tools like..., the Shilatifard Lab created a very quick and efficient way to learn more about gene regulation. Find...Research Campus (Aggarwal et al., 2025).In this latest work, the team designed and screened a large library...making it ideal for video recordings of large populations of synapses and deep-brain fiber photometry. ...mammalian expression and AAV plasmid sets launching later this year! Find Addgene's own Lentiviral backbone...Glypicans By Ashley Waldron Glypicans are important modulators of cell signaling pathways during embryonic development... -
To Codon Optimize or Not: That is the Question
TypeBlog Post...rate of translation and thus protein expression. In fact studies have shown that translational efficiency...particular organism. Why is codon usage important? Translation and protein synthesis relies on transfer RNAs...efficiency is correlated with codon bias across all endogenous genes in E. coli and S. cerevisiae (Tuller et.... Image from Mariana Ruiz Villarreal. By the late 1980s, scientists even created a codon adaptation... 2000 the Ikemura lab created the Codon Usage Tabulated from GenBank database (CUTG), that provides an...on an organisms codon usage bias to increase translational efficiency and thus protein expression without...an organism that contains expression limiting regulatory elements or use a non-canonical code (Gustafsson... -
New Tool for Lineage Tracing: The ClonTracer Library
TypeBlog Post...the resistant populations. In fact, 88% of the barcodes within the resistant populations were shared by...screening with lentiviral pooled shRNA libraries. Later, Bhang says, “When we developed this tool, there...library to determine whether or not cancer cell populations resistant to drug treatments arise during treatment...treatment or are preexisting in the parent population prior to the start of treatment. They hypothesized...hypothesized that, if they labeled the parent cell population using the library, propagated it, separated it into...cells that represent the preexisting resistant subpopulation 2. Resistant cells among the separate replicates...that are present at less than 0.1% of the total population are easily be missed. The ClonTracer library ... -
Early Career Researcher Toolbox: Free Online Molecular Biology Tools
TypeBlog Post...ratio calculators Lab math calculators These calculators can help you with common calculations performed...lab. Molarity calculator Promega's Biomath Calculators Primer resuspension calculator (sign-in required...sequences to sequences in a database ExPASy translation tool: Translates a DNA sequence using all six open reading... Cloning ligation reaction calculators These links can help you calculate how much insert and backbone...Annotates features, BLASTs, aligns, digests, and translates a sequence. NEBCutter2: For finding restriction...information, such as expression patterns, post-translational modifications and polymorphisms Codon optimization...Addgene's Analyze Sequence tool. DNA sequence manipulation tools Sometimes DNA sequences need to be “cleaned... -
Plasmids 101: Common Lab E. coli Strains
TypeBlog Post... mk+) Unmethylated DNA not degraded, cell still can methylate DNA hsdS(rk-,mk-) Unmethylated DNA not...from two individual isolates, the K-12 strain and the B strain. K-12 was isolated from a patient in 1920...pathway that cleaves methylated cytosine DNA Allows for uptake of foreign (methylated) DNA mrr, Δ(mcrC-mrr...that cleaves methylated adenine or cytosine DNA Allows for uptake of foreign (methylated) DNA recA, ...plasmids that should not be Dam or Dcm methylated, allows for methylation sensitive restriction enzymes to ...renaming samples throughout history. It was likely isolated in 1918 but was first referred to as “B strain...routine cloning, cloning unstable DNA, preparing unmethylated DNA, and more. Many mutations that make these... -
Polymerase Chain Reaction Overview and Applications
TypeBlog Post...strands of the template DNA first have to be separated. This occurs by heating the dsDNA template to a point...categories of multiplex PCR: Single template PCR reaction - one template is amplified using several forward... reverse primer sets. Multiple template PCR - multiple templates with different primer pairs that align...invented in the early 1980s by Kary B. Mullis who later shared a Nobel Prize in Chemistry for his work. ... in temperature. Taq was first identified in the late 1960s during research at hot springs in Yellowstone...polymerase, PCR requires free nucleotides (dNTPs), template DNA to amplify from and unique single stranded... primers can anneal to the single stranded DNA template strands. DNA polymerase is also stable at this...