We narrowed to 1,053 results for: FER
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TypeBlog Post... Types of ELISA There are four different types of ELISAs, which differ in the way the antigen is detected... to run an ELISA in your lab! References and resources References Boguszewska, K., Szewczuk, M., Urbaniak...Antibodies are used in many different experiments that require scientists to detect proteins in their...antibody and the detection antibody recognize different epitopes on the target protein, so they do not... for which multiple antibodies that recognize different epitopes are available; this type of ELISA is ... are coated with another protein — known as a reference antigen — that can also bind to that antibody....antigen as the other types of ELISAs require two different antibodies. As mentioned above, it can also be...
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Pathways Over Time Plasmids Engage Students in Functional Genomics Research
TypeBlog Post...section, teams are assigned different groups of three genes selected from different parts of the Met pathway...first select a multi-gene pathway to study and a reference organism where deletion strains are available....Students next transform deletion strains from the reference organisms with the overexpression plasmids. Finally...species has a similar function to the gene in the reference species. We have been using yeast models (3, 4...yeast, Saccharomyces. cerevisiae, makes a great reference organism for the project because it is non-pathogenic.... Over time, the two genomes have become very different due to a whole genome duplication and extensive...cloning to insert the coding sequences for ten different MET/Met genes (Figure 1) from the two yeast species... -
Tips for Titering Your Lentiviral Preps
TypeBlog Post...drawbacks of different methods (for comprehensive protocols for all of the methods discussed here refer to Kutner...the correct transfer plasmid was used in the transfection; if preparing several different lentiviruses...assaying for expression of a gene carried on the transfer plasmid or quantifying the number of viral copies...resistance-genes, or the transgene itself. Many researchers prefer to design primers that target the common features...utilizes the antibiotic resistance genes carried on transfer plasmids. Target cells are transduced with serial...that standard conditions be used when comparing different batches of virus. In addition, some viral preps...step of a successful transduction experiment. References 1. Kutner, Robert H., Xian-Yang Zhang, and Jakob... -
Gaining Leadership Skills Volunteering at a Professional Organization
TypeBlog Post...to learn how to adapt to different situations and, in particular, to different styles of leadership. As... one gain such experience? Your institution may offer occasional workshops on leadership and management...to learn more. Having met many people at that conference, I later became involved with the NPA beyond ... the Committee which I then led for 5 years. Different leadership styles Being an effective leader requires...requires you to understand how to work with many different types of people both above and below you. During...relationships with these individuals who often had different styles from their predecessors. Changes were implemented...mission of the NPA. You must accommodate many different types of people in order to harness their strengths... -
Viral Vectors 101: Systemic Capsids
TypeBlog Post... in mice Many systemic capsids express differently in different mouse strains, a phenomenon that we are...And these differences occur not just between mice and NHPs; some capsids show both different efficacy ... systemic capsids. After some consideration, we offer this definition: A systemic capsid is a capsid that...Organism Mouse Strain-Specific Tropism? Reference AAV-PHP.B* CNS (broad) Mice, rats Yes...sex-independent and does not show significant differences in transduction efficiency between C57BL/6J and...transduction efficiency varying from 10-70% in different regions of the brain (Ravindra Kumar et al., 2020.../cJ and CBA/J mice. AAV1-X1 was developed by transferring the 7-mer peptide region from variable region... -
Promoters
TypeGuide... Plasmid Reference Molecular Biology Reference Promoters Promoters Definition A promoter is...Addgene's molecular biology reference material covering promoters, transcription and the transcription...mRNA transcript produced. The antisense strand is referred to as the template strand or non-coding strand...transcription of DNA into mRNA. Promoter binding is very different in bacteria compared to eukaryotes. In bacteria...promoter region. Each sigma factor recognizes different core promoter sequences. Operons Although bacterial...regulation, like operons. Operons are a cluster of different genes that are controlled by a single promoter... types of RNA polymerases that all transcribe different genes. RNA polymerase I transcribes genes encoding... -
Common Injection Routes in Mice
TypeBlog Post...discomfort of the mice, and restraint method. Many different substances can be injected, including cells, drugs...through the tail vein — many researchers will simply refer to these as “tail vein injections.” However, they.... They are a popular choice for administering different drugs and viral vectors. Like IV injections, intraperitoneal...flat, and easily accessible (like the back) is preferred. A common use of intradermal injections is studying...techniques may come in handy. These techniques are referred to as “instillation” or “gavage,” as they do not...as both procedures target the lungs. The main differences are that intranasal is easier, less invasive,...be flexible or metal, depending on researcher preferences. It sounds complicated but has a pretty low learning... -
Antibodies 101: Conventional vs Spectral Flow Cytometry
TypeBlog Post...overlapping markers. Compensation/reference control(s) Compensation or “reference” controls are samples stained...spectral flow cytometry are more alike than they are different, there are a few aspects in which spectral flow...complex mathematical algorithm and single stained reference controls to distinguish one fluorophore from another... Figure 3: Similarity index across 12 different colors on a three laser spectral flow cytometer...conventional or spectral flow. In spectral flow, reference controls tell the software to look for that exact...is not the same as your single color control. Reference controls: Beads or cells? Compensation beads are...new panel on a spectral cytometer, you prepare reference controls of both beads and cells for a single ... -
Tips for Using BLAST to Verify Plasmids
TypeBlog Post... of the plasmids in our repository with known reference sequences, such as full plasmid sequences provided...BLAST, which includes a simple explanation of the different BLAST programs, databases, and elements of the...The blastp and blastx programs are optimized differently and you may want to select one (or both) depending...you want to verify. We will delve into these differences below. Optimizing blastn searches On the Standard... a Sanger sequencing result to a single known reference sequence or to a BLAST sequence database. If you...two or more sequences” checkbox and paste your reference sequence into the Subject Sequence box that appears...BLAST searches. If you do not know the exact reference sequence for your result, choose one of the BLAST... -
What’s in Your Tube?: A Quick Guide to Measuring DNA by Spectrophotometry
TypeBlog Post...Addgene blog Plasmid Preps: Different Purity, Different Quantities, Different Uses What's the Best Way to... our blog and website. References and Resources References Ahlfen SV, Schlumpberger M. Effects...Each of these contaminants will have a slightly different impact on the spectra of a mixed sample. ...A260/230 of ~2.0. However, let’s break down how different contaminants impact these ratios. Protein contaminants...significantly at low concentrations. The elution buffer you use will also affect how accurate your measurements...give more variable absorbance readings. A Tris-buffered solution tends to produce more consistent readings... instrument you use and check out some of the references we have provided below. And if you do have trouble... -
Uncovering Ancestral Bias in CRISPR Research
TypeBlog Post... that differences in gene expression could explain why some ancestry groups were differentially dependent...ancestry-associated genes. What does the reference genome actually reference? The CRISPR guides used in the screens...done in this preprint. Resources and references References Germline variation contributes to false... were designed to have a perfect match to the reference genome – even single mismatches within a CRISPR...introduce significant bias into the results. But the reference genome does not represent the diversity of genetic...understand how the use of a primarily European reference genome could affect their analysis. Their work...these and any other CRISPR screens using the same reference genomes and libraries. Further complicating the... -
Tips for Screening with Yeast Two Hybrid Systems
TypeBlog Post... the split-luciferase system, intein-mediated splicing reconstitutes functional luciferase only when fusions...when separated (2), and that DBD and TAs from different systems could be combined effectively (3). In ...target gene, in this case a reporter gene (e.g. luciferase or GFP), regardless of whether it interacts with...sequence of the DBD. The DBD-POI fusion (commonly referred to as the “bait”, Figure 2b) cannot activate reporter...interact, this will bring the POI-TA fusion (commonly referred to as the “prey”) in close enough proximity to... fusions of the two halves of the luciferase protein interact and enable intein splicing (5). Screening...a more vigourous screen is to use a number of different bait and prey vectors. This has been shown to ... -
Tips and Tricks for Using Golden Gate Modular Cloning (MoClo)
TypeBlog Post...experiments. The term ‘insert’ refers to plasmids carrying each part, ‘vector’ refers to acceptor plasmids, and...MoClo guide for all the basics of the process. Also refer to Figure 1 for a visual overview! Figure...vectors and parts you will be using during the different levels of your MoClo assembly. Know your process...dictated by four-base overhangs that are paired with different part types (e.g. 5’-GGAG and 3’-TACT flanking ...ensure that these would be interchangeable between different laboratories. Therefore, choosing acceptor vectors... Example Level 1 assembly. The choice between different Level 0 vectors depends on the four-base overhangs...MoClo plate, always do so in cold conditions and preferably on dry ice. Careful use of your glycerol stocks... -
Plasmids 101: Shuttle Vectors
TypeBlog Post...protects against any of them. But different aminoglycosides work on different host species: kanamycin targets... unrelated host species, even from completely different kingdoms of life. That’s convenient for researchers...experiments in complex eukaryotic cells, but would prefer to grow, clone, and manipulate their vectors in...with BioRender.com. How are shuttle vectors different from other plasmids? If we all use the same molecular... Shuttle vectors have to address several big differences in the ways vectors are used across species: ...resistance gene on your vector might require two different selection molecules! It all depends on how the...Auxotrophic selection Another option is to use a different method of selection entirely. Auxotrophic selection... -
Twenty Years of Sharing: Addgene's Viral Vector Service
TypeBlog Post... of the vectors in Addgene’s catalog are offered in different serotypes. In fact, the 879 viral vectors...these tools can be to use. AAVs, which can target different cell types depending on their serotype, are particularly...to researchers around the world. While we still offer many resources for producing vectors from plasmids...93,491 viral vector preps with researchers in 45 different countries — and as of 2024, we’ve distributed ... CRISPR, where we dove fairly deeply into the different types of tools scientists were using/depositing...prioritization happens for good reasons. We began offering our viral vector service because we realized that...successive generations developed ever since. GCaMP6 was offered through our viral vector service in 2016, and it... -
Viral Vectors 101: Pseudotyping
TypeBlog Post...virus: Lowering cytotoxicity. Different envelope proteins have different levels of cytotoxicity and the...Altering sensitivity to serum. Different pseudotyped viruses are differentially inactivated by nonspecific...Table 1 (Cronin et al., 2005) References and Resources References: Crawford KHD, Eguia R, Dingens AS...protocol for generating lentivirus, but you use a different envelope glycoprotein instead of the wild-type...Lentiviral production uses three plasmids: (1) The transfer plasmid, (2) the envelope plasmid, and (3) the...review articles to find tables and information on different viral membranes, tropism, and advantages and disadvantages... Jennifer Tsang... -
Bacterial Toxin-antitoxin Systems as Molecular Biology Tools
TypeBlog Post...more stable than the methyltransferase. When a plasmid is lost, the methyltransferase is degraded and/or...of CcdB (toxin) and CcdA (antitoxin) where CcdB inferes with DNA replication by binding the GyrA subunit...composed of restriction endonucleases and methyltransferases. Restriction endonucleases cleave DNA at ...specific nucleotide sequences. To counter this, methyltransferases add methyl groups to bases at specific nucleotide...address a diverse set of biological inquiries. References Ogura, Teru, and Sota Hiraga. "Mini-F plasmid...genes that couple host cell division to plasmid proliferation." Proceedings of the National Academy of Sciences...Cara E., and James B. Kaper. "Use of stabilized luciferase-expressing plasmids to examine in vivo-induced... -
Using Ultrasound to Image Bacteria in vivo: Acoustic Reporter Genes
TypeBlog Post...Administration of Substrate: Some luciferase reporters, such as Renilla luciferase (RLuc) or NanoLuc, require...bacterial reporters that use fluorophores and luciferases to track bacteria in real time, but each of these...together genes from gas vesicle operons from two different bacteria, Bourdeau et al created two constructs... 1 (arg1) and acoustic gene 2 (arg2). The key difference between arg1 and arg2 vesicles is the amount ... invisible to ultrasound, which allows for differentiation of arg1 and arg2 ultrasound signals. This also...and arg2 plasmids are available from Addgene! References 1 Bourdeau, R.W., Lee-Gosselin, A., Lakshmanan...Blog Learn more about in vivo imaging tools The luciferase reporter gene The green fluorescent protein reporter... -
Viral Vectors 101: Parts of the AAV Packaging Plasmid
TypeBlog Post...gene which differ between the AAV serotypes are responsible for serotype-specific differences in tissue...blog post to learn more about the AAV transfer plasmid! References: Naso MF, Tomkowicz B, Perry WL III...proteins needed for the virus to replicate, and the transfer plasmid which contains the viral genome. In today... proteins. Alternative splicing generates the different C-terminal regions of the Rep proteins. While ...Replication initiates from the AAV genome ITRs on the transfer plasmid, which contain regions of dsDNA. To generate...the AAV p40 promoter. Alternative splicing and differing translational start sites generate the three VP...was engineered Learn about the parts of the AAV transfer plasmid Resources on Addgene.org Learn about... -
Antibody Neutralization Response Against Pseudoviruses Expressing SARS-CoV-2 Spike Protein Variants
TypeBlog Post...19 pandemic,” says Balazs. References and Resources References Cele S, Gazy I, Jackson L, Hwa S-...neutralization effectiveness of current vaccines differed depending on the variants (Garcia-Beltran et al...plasmids which encode spikes found on all of the different circulating variants. This allowed us to create.... In their assay, the pseudoviruses express a luciferase reporter which is used as a readout for infection...variants. Yet, the B.1.351 variant, which has only 9 different mutations compared to the wild-type, escaped neutralization...Garcia-Beltran et al., 2021 with permission. Difference in neutralization after one dose and two doses..., this study was the first to compare so many different strains. It was also the first to perform neutralization... -
Single-cell tracking of lineage and identity with CellTag
TypeBlog Post...Direct reprogramming describes the process where differentiated cells are turned into a cell type of choice...identifier and allows cells to be tagged with different CellTag libraries at multiple timepoints during... (iEPs), a self-renewing cell type that can differentiate into hepatic or intestinal cell types. MEFs ...inefficient. Cells were sequentially tagged with different CellTag libraries at three time points during ...MettI7a1 encodes an uncharacterized putative methyltransferase. Adding Mettl7a1 to the standard Foxa1-Hnf4α...are undergoing identity changes, such as the differentiation of induced pluripotent stem cells or the clonal...visualization tool. Check out the CellTag webpage! References Biddy, Brent A., et al. "Single-cell mapping ... -
K. phaffii: Rising to the Occasion
TypeBlog Post...have risen into yeast expertise! References and Resources References Liu, Wei, et al., From Saccharomyces...applications in food science and biotech due to its fermentation abilities and other useful traits. The “biotech...lists some of the biological commonalities and differences between K. phaffii and other yeast strains. ...aerobe Number of chromosomes 16 3 4 Preferred carbon source Glucose Glucose Glucose, methanol...Applications for K. phaffii There’s a number of different uses for the phaffii-lous strain. Protein expression...peroxisome studies since their peroxisomes will proliferate upon a media change into methanol and peroxisomal...peroxisomal studies on biogenesis, degradation, and proliferation. Genome manipulation K. phaffii’s genome has... -
Plasmids 101: How to Verify Your Plasmid Using a Restriction Digest Analysis
TypeBlog Post...add loading buffer to your digest reactions before loading them. The glycerol in the buffer will make sure...based on the predicted sizes and organization of different features within the plasmid. Restriction analysis...can search NCBI for YGOI to find the particular reference sequence if necessary. The example plasmid on ...fragment having increased intensity to serve as a reference band. The uncut DNA (lane 2) shows 3 possible ...visualize the full size of your construct. Consider buffer and temperature compatibility when digesting with...versions of the endonucleases and/or supply custom buffers as means to avoid this issue. For your gel: ...in the gel well and the dyes provide a visual reference point so you can easily assess how far the gel... -
From Lab Bench to Leadership: Transitioning into Management as a PhD
TypeBlog Post...skills that were quite different from mine. Learning to bridge those differences was a pivotal moment in...technical problems in the lab, management involves a different skill set: mentoring, setting strategic goals,... day-to-day details. Ignoring individual differencesManaging a team isn’t “one size fits all”. Each team... needs. For instance, I had one colleague who preferred detailed instructions and regular check-ins, which...autonomously. Failing to recognize and adapt to these differences could have led to frustration, micromanagement... particular, served as a great "baby project," offering a supportive environment to build my management...noticed tension between two team members with differing approaches—one detail-focused and the other big-picture... -
Viral Vectors 101: Biosensors
TypeBlog Post...imaging for advanced monitoring of different factors, in different or the same cellular location, all ...covered with packaging plasmids! References and Resources References Bhalla N., Jolly P., et al. Introduction...biosensors provide quantifiable readouts for levels of different chemicals, hormones, proteins, etc., that you ...as calcium. This varied component, which we will refer to as the analyte, needs to be specifically recognized...and zinc. These ion sensors can be targeted to different cellular locations or tissues depending on the...acceptor of a FRET pair on actinin will produce different signals based on changes to the structure of actinin...organisms, but AAVs make it possible. In AAV systems, different serotypes can be used to affect or determine viral... -
Antibodies 101: Monoclonal Antibodies
TypeBlog Post...antibodies differ from other types of antibodies? How monoclonal antibodies are made “Monoclonal” refers to ...for your experimental needs. References and resources References Bradbury ARM, Trinklein ND, Thie ...experiments, you may be curious about all of the different kinds of antibodies that are available. One common...heterogenous mixture of antibodies that recognize many different epitopes on the same protein - are more likely...to produce monoclonal antibodies. Genetic drift refers to changes in the nucleic acid sequence of the ...impacts the specificity, avidity, and number of different antibodies produced by the hybridoma. Image from..., Aldred SF, Bestagno M, Burrone O, Maynard J, Ferrara F, Trimmer JS, Görnemann J, Glanville J, Wolf P... -
Plasmids 101: Screens vs. Selections
TypeBlog Post...in. The differences They say the devil is in the details - and that’s where the differences in these... RNAi resources and go fishing! References and resources References Wang, T., Wei, J.J., Sabatini, D....? If you’re thinking, ‘wait, those terms mean different things?!’, you aren’t alone! We’ve noticed a lot...selections The common goals The confusion in differentiating between a screen and a selection isn’t surprising... you would individually treat cells with many different drugs and then perform an assay to look at an ...enhancer/suppressor screens. Selections Selections differ from screens in that only survivable manipulations...experimental question. Now that you understand the difference between the two, it’s time to check out our CRISPR... -
Viral Vectors 101: Optogenetic Tools
TypeBlog Post...excitatory and inhibitory channels activated at different wavelengths of light (Vierock et al., 2021). Step-function...stay on until a second pulse of light, with a different wavelength, turns it off, allowing the cell to... secondary signaling pathways. There are many different opsin (natural and engineered proteins responsive...pathway to activate various protein regulators at different points in the pathway. Photoswitches are great...successive steps along a pathway, there can be very different responses to long vs. short stimulation times ... & Cui, 2015). You’ll need to test for these differences when designing your experiment. Finding the ...available to help light your path! Resources and references Recommended reading Abreu, N., & Levitz, J. (... -
Finding Your Perfect Job After University
TypeBlog Post...’s of working in different sectors. Luckily, I have worked for a variety of different organizations, so...overview of my experience and how I felt about the different positions to enable them to decide for themselves...effectively. I had to learn how to cope with a different climate and culture, and also needed to be resourceful...very quickly; as soon as I learned how to do the different tests and became efficient, I then started to ...diagnostic tool for the detection and diagnosis of different types of pancreatic cancer and highlighting which...were keen for me to become involved with many different aspects of the company and gave me the freedom... and travel to meet scientists, making my job different every day. I love the freedom to design and develop... -
Building Global Connections with the International Mentorship Program USA-EUROPE
TypeBlog Post...international mentoring conference held at the University of Valencia (Spain). At this conference, mentors and mentees...professional development and networking resources offered by programs like IMP USA-Europe not only provide...international mentors. Universities from five different geographical locations in Spain were enrolled:...mentees held scheduled monthly progress video conferences and had real-time correspondence via e-mail throughout...Mentorship Program and the International Mentorship Conference In addition to a pre-program self-assessment ... exchanged impressions of the IMP experience. Conference highlights included remarks by the Spanish Secretary...community overseas. Official representatives from different Spanish universities and high level public and...