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Showing: 41 - 60 of 776 results
  1. Plasmids 101: In-house NGS Plasmid Quality Control Now at Addgene

    Type
    Blog Post
    Published
    April 6, 2021, 12:30 p.m.
    ...high-quality isolated DNA samples of sufficient quantity for sequencing. This process is completed in a plate format...MiSeq that takes about two days to complete. After the run completes, we begin our assembly process. Again...holes are then filled with other samples in our queue such as viral samples for Viral Genome Sequencing (... libraries.  Viral samples are filled into the same process as our normal Complete Plasmid Sequencing ...unique barcodes per sample so we can assign sequencing reads to the correct sample. The PCR is then performed... to remove any template DNA and primers.  After performing extensive QC on that sample, we’ll then load...yielding anywhere from two to six plates of 96 samples per week. This is where our new process will begin...
  2. Lab Automation at Addgene

    Type
    Blog Post
    Published
    March 22, 2018, 1:28 p.m.
    ...pipette samples in and out of it, you can set up a procedure for it using the Biomek FxP. For example, we ... pretty simple. By clicking a few buttons you can quickly tell the Biomek FxP how much sample to pick ...easy to spread out your samples. This can be useful if you’re transferring samples from 96 wells plates ... from many bacterial samples at the same time as opposed to preparing each sample individually. Enter ...do a lot of aliquoting. Simply program the pipette with how much total sample you need and the volume ...provide you with some tips on how to automate some simple processes in your own lab. Automating bacterial...mobile pods - one pod can pick up 96 tips for easy sample transfer between 96 well plates. The second pod...
  3. Advice on Career Paths and the Green Card Process for International Researchers and Entrepreneurs

    Type
    Blog Post
    Published
    Dec. 20, 2017, 2:33 p.m.
    ...cap” subject H-1Bs. The H-1B allows U.S. employers to employ foreign workers in specialty occupations....work-authorization is strictly limited to employment by the sponsoring employer. On April 18, 2017, President Trump... H-1B allows employers to avoid the 85,000-visa numerical quota. Four types of employers are not subject... require the H-1B employee to work at one of the first three categories of employers. H-1B petitioners...States. There has been a growing shift away from employers sponsoring individuals for green cards because... As of September 2017, USCIS received 116,224 employment based green card applications and approved 91,023... to find the perfect job immediately after you complete your Ph.D. or postdoc. Foreign national researchers...
  4. Getting to Know Expansion Microscopy

    Type
    Blog Post
    Published
    June 20, 2023, 1:15 p.m.
    ...we just made the sample bigger? In ExM, and its various derivatives, biological samples are enmeshed in...label) your sample (i.e. cultured cells or tissues).  Step 2: attach anchors to your sample that will link...times, and the physical properties of the sample itself. For example, cultured cells are typically easier ...structure. For example, cytoskeletal structures that form continuous lines in pre-expanded samples can sometimes... popularity with an abundance of protocols and examples of applications from across disciplines now available...the number of specific targets you can label in a sample. Super-resolution microscopy (SRM), a family of... its original size. Depending on the protocol, samples can be expanded to ~4-10x linearly! This expansion...
  5. Plasmids 101: Colony PCR

    Type
    Blog Post
    Published
    May 12, 2016, 2:30 p.m.
    ...briefly boiling the sample before use or by directly adding a small volume of the sample to the PCR reaction...your experiment. Shorter amplicons tend to be better. Shorter amplicons make for shorter PCR programs...restriction enzyme digest; however colony PCR can accomplish the same thing in less time and for less money...polymerase) using the supernatant of lysed bacteria as template; and 3) run your PCR product on a gel to analyze...yes or no” kind of test, with a positive clone amplifying a product and a negative clone resulting in no...orientation-specific primers. Blunt end cloning is an example of when you might want to know the orientation ... insert and one primer anneals to the insert. A simple way to create this type of primer pair is to mix-and-match...
  6. CRISPR 101: Homology Directed Repair

    Type
    Blog Post
    Published
    Jan. 26, 2023, 2:15 p.m.
    ...modifications exist in the template DNA. There are several unique HDR mechanisms, but all templated-repair pathways...encoding your repair template, then uses reverse transcriptase to generate the complementary ssDNA. Easi-CRISPR...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...recombination intermediates can then resolve to complete the DNA repair process Homology directed repair...mechanism that notably does not require a donor template and thus won’t be covered in detail here. Classical...
  7. AAV Titers: Where Do They Come From And What Do They Mean?

    Type
    Blog Post
    Published
    Nov. 15, 2017, 3 p.m.
    ...each individual sample, this will reduce convenience and comparability because each sample with be quantified... low-concentration samples can also behave differently in PCR, even if both samples fall within the linear...reference sample of known titer, which is at a higher titer than the AAV RSM. By using these samples in all... titer values of new AAV samples. We also typically quantify our AAV sample by two qPCR assays and compare...that category? Okay, let’s play. I’ll list the examples and you try to guess the category: ELISA...qPCR...affected by many experimental factors. To list some complicating factors for quantifying AAV: qPCR efficiency...the AAV genome, caused by repeats and self-complementarity of the AAV genome and the ITRs. qPCR efficiency...
  8. Finding nucleic acids with SHERLOCK and DETECTR

    Type
    Blog Post
    Published
    April 16, 2020, 1 p.m.
    ...or RNA from a sample is first amplified using RPA (recombinase polymerase amplification) or reverse transcriptase...transcription to convert amplified DNA to RNA for subsequent detection by Cas13. This amplification step in combination...with Cas13 to amplify the signal of a single target. Csm6 can cleave ssRNA complementary to a crRNA of...your DNA or RNA of interest within a given sample is simply determined by the number of bands present ...sensitivity, the DNA is first amplified through isothermal amplification by RPA. When Cas12a-cRNA base... and/or are too expensive, time-consuming, and complex to use outside of standard laboratories. In the...protein variants, Cas13, and Cas12a, to develop simple, portable, and inexpensive platforms to reliably...
  9. Plasmid Cloning by PCR

    Type
    Blog Post
    Published
    March 29, 2016, 2:30 p.m.
    ...to the stop codon (TGA, in this example). Assuming you are amplifying from plasmid DNA (rather than from..., but we need to use the reverse complement to get PCR amplification. We can start similarly, taking the...generate the reverse-complement of this sequence so that we can successfully amplify the ORF. You can generate... to be amplified (the ORF in this case), not the Tm of the entire primer. If you are amplifying from a... a plasmid or simple template, there is very little chance for mis-priming, so you can use a pretty wide...In its simplest form, PCR based cloning is about making a copy of a piece of DNA and at the same time...detailed refresher on the downstream steps. For this example, we will describe how to copy a cDNA from one vector...
  10. PCR Applications for Copy Number Variation Assays

    Type
    Blog Post
    Published
    April 26, 2022, 1:15 p.m.
    ... reference sample with two copies of the gene (Ma, 2014.) As with all qPCR assays, samples, standard curves...experiment?  Complexity of the gene of interest Some gene sequences are harder to amplify and quantify...reference sequence present in the same amount in all samples (usually to a ubiquitously expressed, one-copy ...housekeeping’ gene), and quantified relative to a 'normal' sample with known copy number set as the expression baseline...since you’re looking at the amount of DNA in your sample relative to your normal control - you can set up...number (RQ value) matches the copy number of your sample. In that case, an RQ value of one (or, more realistically...fluorescent probe and quencher to quantify specific amplicons.  Sybr has high background noise, due to the large...
  11. Deep Dive: Fixing and Permeabilizing for Immunofluorescence

    Type
    Blog Post
    Published
    Aug. 30, 2022, 1:15 p.m.
    ... permeabilize a sample. But you can also use organic solvents after fixing your sample with a cross-linker...the point?  Fixation allows you to freeze your samples in a given state or point in time. You want to ...processes while maintaining the structure of your samples, the relationships between cellular components,... molecules and it is great for preserving your samples and maintaining cellular and tissue morphology....formaldehyde solutions.  Along with preserving your sample, cross-linking can block the epitope of some targets...sensitive to cross-linking, but it doesn’t preserve sample structure quite as well as a cross-linker. This...during fixation with these chemicals, which impacts sample structure and could also cause your target to be...
  12. Antibodies 101: The Basics of Western Blotting

    Type
    Blog Post
    Published
    March 8, 2021, 2:41 p.m.
    ...size and density present in all samples. Uneven sample loading or incomplete protein transfer causes inconsistent...cells? Immunoblotting or simply the western blot, or western, is one of the simplest methods to detect the...thiols, to cleave disulfide bonds. Load the samples, one sample per lane, onto the top of a resolving gel...Figure 1: Overview of the Western blot process. The sample, a mixture of protein is separated in a gel, transferred...to detect a single, specific protein within the complex mix derived from cells or tissues. Westerns are...is the first step of a western. To prepare the samples for SDS-PAGE, measure the protein content and normalize...normalize to ensure equivalent loading. Denature the samples to their primary amino acid sequence by boiling...
  13. Developing Lab Management Software for Biology

    Type
    Blog Post
    Published
    Aug. 25, 2016, 2:30 p.m.
    ... little simplified): Find the appropriate glycerol stock within our freezers Pick the sample into the...success or failure: In our second example we’ve added some simple but critical logic. Some steps fail...proper location To keep ourselves from mixing up samples and to ensure that everything is grown successfully...needs to handle these cases. The following code examples show how software can be structured to allow for... for the messiness of biology. These examples are intentionally trivial, but they're here to help tell...tell this story. In this first example to the right (# this will make you sad),  someone has put in a request...’s time for our lab technicians to retrieve the sample and get it ready for shipping. In the first case...
  14. Deep Mutational Scanning with One Pot Saturation Mutagenesis

    Type
    Blog Post
    Published
    Feb. 22, 2017, 3:30 p.m.
    ...the template. The opposite is true if the sense strand is nicked for template formation: template will...mutagenesis. Error-prone PCR: This method amplifies the wild-type template with a “sloppy” version of PCR that...synthesize a complementary mutant strand (step 2 and 3). Then the uracil-labeled template strand is degraded...low primer-to-template ratio is used to promote annealing of one primer to each template. The PCR product...and easy technique that can be used to generate complex libraries of mutant plasmids ready for deep mutational...in protein activity. See Natarajan et al for an example of this. Plasmid library generation prior to one...). It uses a uracil labeled wild-type ssDNA as template for a site-directed mutagenesis PCR that uses ...
  15. Truncated gRNAs for Regulating Gene Expression

    Type
    Blog Post
    Published
    Jan. 10, 2017, 3:37 p.m.
    ...DNA strands complementary and non-complementary to the gRNA, respectively. When complexed with a truncated...full-length gRNA (20nt complementarity to target site) or truncated gRNA (≤15nt complementarity to target site...with which it is complexed rather than the protein itself. When native Cas9 is complexed with a gRNA that...transcriptional activator to the Cas9-gRNA complex. When this complex is directed to a target upstream of the...bioengineering, as it has facilitated the development of a simple and scalable means of making targeted genetic edits... directed to virtually any genetic locus when complexed with an appropriately designed small RNA, or guide...conventionally contains a 20-nucleotide sequence that is complementary to the target site, or protospacer, in the genome...
  16. The Materials Science of Optogenetics Experiments

    Type
    Blog Post
    Published
    Sept. 17, 2015, 2:30 p.m.
    ... and implant. A steady stream of photons from the laser to the patch cable to the ferrule implant must...opsin through a small piece of fiber optic cable implanted into the animal’s skull (right). The fiber optic...skull using dental cement (a similar procedure as implanting a guide cannula). A fiber optic patch cable is...various steps required to produce your fiber optic implant. Companies such as Thor Labs and Precision Fiber.... First, the length of the fiber optic for the implant depends on the dorsal/ventral location of your ...that is emitted from the end of the fiber optic implant scatters a great deal once it enters tissue, placement...penetrate brain tissue a short distance so ideal implant placement should be about 0.4-0.5mm above the site...
  17. Antibodies 101: Validation

    Type
    Blog Post
    Published
    March 24, 2022, 1:15 p.m.
    ...bind to - particularly when you start using complex samples such as whole cell lysate or tissue sections...antibody signal in the retinal sample, but little to no signal in the liver sample, which you do (C), so your...signal in samples that have had the target protein expression experimentally increased. The simplest version...require variable expression of your target across samples - it is hard to distinguish between specific, invariable...proteomic and transcriptomic datasets already exist.   Example: You want to use an antibody to examine the levels...there is a wealth of transcriptomic data from this sample type, so you use your bioinformatics skills (or...Removing (or reducing) the protein of interest in your sample, should lead to reduced or eliminated antibody ...
  18. Antibodies 101: ELISA (Enzyme-linked Immunosorbent Assay)

    Type
    Blog Post
    Published
    Aug. 24, 2021, 1:15 p.m.
    ...wells with an experimental sample allows for detecting one protein from the sample. A direct ELISA has many...require scientists to detect proteins in their samples. One technique that relies heavily on antibodies...principle of an ELISA is that any antigen within a sample adheres to the well (either directly or by binding...antibodies coating the wells to capture antigen from a sample, whereas antigen is bound directly to the wells...protein you are interested in detecting in your sample. When an ELISA kit is ordered, the wells are typically...already coated with the antibody. Then, you add your sample to the wells, and the antibodies bind to your protein... used to detect a single protein within a mixed sample. However, in this case your protein of interest...
  19. Transferable Skills Guide: Time Management

    Type
    Blog Post
    Published
    Dec. 5, 2017, 1:52 p.m.
    ...tasks that can be accomplished quickly and things that will take longer. Completing the quick and useful...useful tasks. The quick accomplishments will likely energize you. For example, let's say you’re doing ...project they’re a part of, completing them will give me some sense of accomplishment. I will prioritize which...its utility) How much time it will take you to complete the task When picking which tasks to actually...will swiftly give you the wonderful feeling of accomplishment while the longer tasks will give you larger...larger payoffs later. Don’t be afraid to accomplish some quick but moderately useful tasks at the expense ...experiment. The first way, it will take you 3 days to complete the entire experiment, but you’ll have to spend...
  20. Fluorescent Proteins 101: Visualizing Subcellular Structures & Organelles

    Type
    Blog Post
    Published
    June 22, 2017, 2:30 p.m.
    ...production site to its final destination. As an example, most secreted proteins are produced in the endoplasmid... the untagged, wild-type protein. You may, for example, validate that the fusion protein localizes properly...visualized with a fluorescently-tagged antibody. By employing “marker proteins” which are known to be a part...intracellular targets. Therefore, it can be beneficial to employ well-characterized marker proteins tagged with ...fusions to visualize subcellular structures. For example, you might use your fluoresent protein fused to...and potentially which other proteins it forms complexes with. These “colocalization” studies give insights...within the same subcellular structure or protein complex. By coexpressing both the marker protein and the...
Showing: 41 - 60 of 776 results