... TF library (aka the MORF Collection) and an accompanying expression atlas, including over 3,500 human...from these sites. The Zhang lab generated a comprehensive library of each unique TF open reading frame...endoderm, and mesoderm). These profiles were then compared to that of reference cell types generated by the... the human fetal expression atlas. Computational analysis was used to infer differentiation trajectories...Previously engineered TF libraries were not as comprehensive as this one, so it is an invaluable tool to ...expression dysregulation event. Diseases are often complex, with multiple layers of dysregulation from either...

...that no component of the overall project gets left undone or is duplicated. With each component of the ...the project completed by an individual who is a local expert in that task (or has the bandwidth to become...result is high quality and the entire process is completed more efficiently. Listen to our podcast interview...desired outcomes. Concern yourself with what is accomplished, rather than detailing how the work should be...in more engaged, successful employees who can accomplish great things.   To read more on this topic and...

...fluorescent proteins, how to do a head-to-head comparison of fluorescent proteins and how to make a well-informed...your selection on a small-scale head-to-head comparative study under conditions that best mimic the intended...protein properties and provides a quick way to compare fluorescent proteins, e.g. see Chudakov et al (...is of no use. Therefore, it is more sensible to compare fluorescent proteins based on their practical brightness...promising fluorescent proteins and to determine and compare their practical brightness in a system closely ...application. In figure 2 we provide an example of the comparison of the practical brightness of two orange fluorescent...

...expressed in cells, generates much less signal than comparable fluorescent proteins. This weak emission hasn... with increased sensitivity and faster imaging compared to previous publications. They also developed ...they successfully imaged multiple subcellular compartments over several minutes using Nano-lantern fusion... fluorescence, so higher concentrations of the compound can be added to the media. Cellular esterase then...producing a constant supply of substrate. Using this compound to excite the Nano-lanterns, Takai et al. continuously... handy. This approach is especially suited to complement optogenetic tools, where light used for excitation...

...all bacteria are naturally competent to take up DNA, they can be made competent through chemical manipulation...Addgene’s blog to learn about making your own competent cells and our protocols page to learn about bacterial... The phagemids are packaged into replication-incompetent phage particles with assistance from a ‘helper... A., and Karen Guillemin. "Multiple phases of competence occur during the Helicobacter pylori growth cycle...Meibom, Karin L., et al. "Chitin induces natural competence in Vibrio cholerae." Science 310.5755 (2005):...

...and reduce needed compensation.    Working with antibodies can get a bit complicated, but hopefully this...time-sensitive, using precious samples, or being compared to other data in a manner that demands high accuracy... reaction to understand if any of your buffer components could affect the reaction. For instance, sodium...detected in the same assay. This is one of the most complex subjects in antibody-based protocols - but thankfully...another channel's detection range. Though you can compensate for this when reading your data, you’ll want ...

...track of computation work comes with new sets of challenges. One challenge with computational analyses... of biologists are finding themselves using computational approaches to analyze large data sets (myself...RNA-seq analysis. I had never interacted with a computer at the command line, and so was really starting...especially since you’ll want to dig in to the computation, but they will serve you well as you perform ...directory: A directory is a file system in the computer and is just another name for a folder. For instance...

...based on size. Whether higher molecular weight complexes are detected will depend on the homodimer affinity...During the experiment, the solution is diluted, complicating the interpretation. Because of this, these methods...fluorescent protein is monomeric without the accompanying data to prove it is worthless. The OSER assay...and biological properties of new fusions can be compared with mEGFP or mTurquoise2, which are established...that you will be using. If you do a head-to-head comparison right, it will be valuable information for the... are engineered can be shared to simplify the comparison by others. Together, we can build a valuable ...

...us to the key question: what is the best way to compare the photostability of different fluorescent proteins...measurements for different fluorescent proteins and by comparing how the fluorescence intensity changes over time...photostability of the fluorescent proteins can be directly compared. An example of a photostability measurement of...fluorescent protein can be identified by a head-to-head comparison of several fluorescent proteins of the same spectral.... In figure 1 we provide an example of such a comparison between cyan fluorescent proteins using widefield... power, the photostability of the variants is comparable (lower panel of figure 1). To avoid changes in...

...specific chromosome. This image represents the composite of fluorescent measurements from red, blue, and...modified GFP-dCas9 and the gRNA scaffold to enhance complex assembly, thereby decreasing the amount of background... labeling efficiency was similar to that of a comparable FISH method. Importantly, they did not observe...with the previously established physical map. In comparing pairs of targets ~2 Mbp apart, they noticed that...that they could evaluate the degree of chromatin compaction even for this small distance! To the authors’...CRISPRainbow generates 6 unique colors and a white composite. gRNAs with two identical hairpin binding domains...

...specific components that are key to the cloning reaction. Understanding the specific components is essential...take up your insert. But exactly how does ccdB accomplish this? Let’s start with a brief history of the...system contains ccdB. A successful insertion will completely replace ccdB with the investigator’s insert of...interest.   CcdB resistant E. coli strains complete the system But ccdB alone isn’t the only key to...protein involves poisoning of DNA-topoisomerase II complexes.” J Mol Biol. 1992 Aug 5;226(3):735-45. PubMed...

... and trolls. People don’t like to connect with complete strangers as it borders on my first rule of networking...’m asked a lot about requesting connections to complete strangers for informational interviews. Many have...option is in the “More…” menu. You can also follow companies and organizations to see their news and job postings...interviews.  Pro tip: You can learn a lot from the company LinkedIn page. This can include news, inclusion...It’s also a great way to keep track of past accomplishments. Follow all the rules of good resume writing...writing. Include examples of concrete accomplishments in both the technical and “plus skills” areas. Include...

...and the efficacy of your competent cells (when they get old, they lose competency). If all the above is ... be sure that the buffers and temperature are compatible between the different enzymes. Always check the...source (i.e. primer3) or provided by the major companies selling PCR reagents. Nowadays commercial polymerases...a general rule, try to use an excess of insert compared to the backbone plasmid; a starting point could...plasmid. Many vectors contain sequences that are complementary to standard sequencing primers. If not, design...

.... Addgene is now as much a tech company as it is a reagent company. I used to have to worry about this...remarkably so for a 90 person company. We were and remain ahead of most companies in creating a welcoming, ...often focus on the excitement of what we are accomplishing and what more we might do. I am grateful every...innovative thinking, and openness to team work.   Company culture Once in awhile I worry a very little ...

...presentation, lost in a sea of data, my mind went completely blank. After several seconds of truly panicked...honest, if my paper hadn’t been ridiculously more complex than the one before it, I don’t think I would have... panicked state, only option one would let me accomplish my goal.   As a scientist, public speaking isn't...dumpster noises were just last week!  Nerves It’s completely normal to be anxious, nervous, and/or apprehensive... in its most difficult form. You’re presenting complex data, to a group of peers who are there to provide...conferences, or even just provide quick updates during a company meeting increases visibility of your work, opens...

...was contributed by guest blogger Alan Wong. The complexity of biological systems can hinder our attempts...simple tool that allowed us to rapidly decode the complexity? The CombiGEM-CRISPR technology was developed...of providing an easy-to-use tool to analyze the complex combinatorial genetic networks underlying your ...mapping the combinatorial genetics that underlie complex regulation in biological systems. The CombiGEM ...new technologies to interrogate and understand complex biological systems. He can be contacted at aslw...transcriptional activation by an engineered CRISPR-Cas9 complex." Nature (2014). PubMed PMID: 25494202. PubMed ...

... do as genetic circuits become larger and more complex? Voigt: If you look at all the products of biology... on genes at different times. It requires more complex synthetic networks. Addgene: What hurdles did you... perspective and you can layer them for more complicated functions. Those things are easy with CRISPR..... There haven’t been enough genetic parts for complexity. We have characterized almost 600 terminators...of a cell. The objective is to give people the complete toolbox for taking on very large genetic engineering...just using what biology has given us. Wood is a complicated material and we can access it, but we are stuck...

...science and collaboration. The field already has comprehensive reference pages and curated databases for scientists... (CeNGEN) The CeNGEN goal is to establish a comprehensive gene expression atlas of every C.elegans  neuron...that is creating the “first virtual organism in a computer.” This project has produced various resources ...four-dimensional contrast interference (DIC) microscopy and computer imaging processing. The combination of these methods...methods provides unique opportunities to develop computational methods to better understand animal development...Hammarlund, Marc, et al. "The CeNGEN Project: The Complete Gene Expression Map of an Entire Nervous System...

... to stop functioning properly or be something completely different than what was originally intended. ...tags, promoters, and other critical functional components. Fun fact! Some older plasmids in our collection...each of their plasmids, from descriptions of key components of the plasmids to partial, full, or annotated...Addgene receives deposited plasmids, they undergo complete plasmid sequencing using an in-house Illumina ...Addgene. The assembled plasmid sequence is then compared to the information provided by the depositor. ... sequence is not available, QC scientists will compare the NGS results to the plasmid information, other...

...that allow their host organisms to thrive in competitive environments. The genes encoding these functions...triumph over your neighbors is to eliminate the competition, and Penicillium isn’t the only organism that... are also less aggressive ways to survive in competitive environments — like by living where no one else...to be active only in the presence of the target compound. These systems are a gold mine of parts for synthetic...Shareck et al., 2004). Plasmid categorization is complex Plasmid classification has shifted over the years...necessarily reflect genetic relationships or plasmid incompatibility. Plasmids may also have more than one function...

...blood clotting, and as we all know, a structural component of bones and teeth. It is an enzyme co-factor,..., a neuron subtype) and specific subcellular compartments for measurements. All of the sensors discussed...calcium concentrations in different subcellular compartments can vary greatly. Additionally, the calcium ...susceptible to artifacts and pH interference, and comparison between experiments can be more difficult due...GCaMP6 only) or mammalian cell expression, and compatible with constitutive or Cre-dependent expression...Genetically encoded calcium indicators to probe complex brain circuit dynamics in vivo. Neuroscience Research...

...significant amount of flexibility compared to a strict single-compatibility sequence like NGG. Nonetheless...NG, a rationally engineered Cas9 with NG PAM compatibility, as the name implies (Nishimasu et. al, 2018...know and love about Cas9, but with broader PAM compatibility. This alternative PAM requirement adds a significant...PAMs and is capable of editing at frequencies comparable to SpCas9. SpRY can also edit NYN PAMs, but with... Ai C, Hu J. In-depth assessment of the PAM compatibility and editing activities of Cas9 variants. Nucleic...

...remodeling. Chromatin is a complex of DNA and histone proteins that compacts cellular DNA into chromosomes...in the compacted region and results in a loss of gene expression. In this way, genes in compacted regions...and tightly bound DNA is to histones, the more compacted it becomes. This prevents the cellular machinery...have huge impacts in the way we study and treat complex or multifactorial diseases, enabling faster diagnosis...

...information directly into the file. Email the completed spreadsheet to [email protected] along with ...used to knockdown expression of mRNAs with complementarity to the shRNA sequence. Empty backbone A plasmid...plasmid data in the pages described below. You can complete these pages sequentially by entering the appropriate...the links at the top of the page. Figure 11: A completed plasmid page for review before submission. Once... right of each data entry page. Once you have completed the data entry process for all of the plasmids...Figure 13: Click the "Submit Deposit" button to complete the data entry. Clicking the "Submit Deposit" ...third party rights holders. Once this process is complete, you will receive a Deposit Confirmation email...

...bacterial strains, like NEB Stable. NEB Stable competent cells lack RecA, a protein that aids in the homologous...helps me figure out if I have enough plasmid to complete my experiment. AAV is usually the limiting reagent...produce more virus because I don’t have enough AAV. Compared to the Addgene AAV Production protocol, I take...concentrate the purified virus. This process can be completed in one long day, or the virus can be stored at...set can be used and samples are quantified by comparing to an AAV standard curve, which is generated from... plasmid. This whole process takes ~3 hours to complete: 1 hours hands-on time and 2 hours for the qPCR...

...while also ensuring that my work gets completed? I want my company to pay for me to attend a conference... How can I negotiate my starting date with the company so they know I’m excited while still being able...want to learn more about a different area of the company. How can I negotiate with my manager to gain experience...conference. How can I negotiate to show the company that investing in me is also beneficial to them? I have an...but I need help from another person/team at the company. How do I negotiate with the person/team for help...

...know that this process only became even more complicated with COVID-19 and standards for hybrid, virtual...without the financial and logistical stress that accompanies traveling for campus visits. This is definitely...where the PhD application cycle becomes much more complex. “How do I reach out to potential mentors?” “Where...very valid questions, and often make an already complicated process even more difficult. I’ve learned that...to be incredibly useful, as it gives a more comprehensive idea of that advisor’s research interests which... for the interview. Having notes close to your computer with things you want to highlight in the interview...

...about a month and a half, without the need for complicated cloning of homology arms. MMEJ: An Introduction...HDR and NHEJ, please see the linked blog posts. Compared to its counterparts NHEJ and HDR, MMEJ doesn’t...strategy looks very similar to HDR, but it is accomplished using much smaller regions of homology, which...strategy looks very similar to HDR, but it is completed using much shorter sequence homologies. Abbreviated...efficiency of PITCh-based genomic insertion would compare to CRISPR sticky-end insertion using the nuclease...Genome-Editing Based Approach for Mapping Multiprotein Complexes in Human Cells.” Cell Rep. 13: 621-633. PMID: ...

...These insights are hard to appreciate without computational support. Indeed, rational sgRNA design is not...experimental applications in CRISPR engineering. When compared to that collective utility, it’s easy to fault...tool unique. The CRISPR Software Matchmaker is composed of these features and enables you to select the... based on their comfort level with operating a computer.  Examples: “offline”, “online”, “CLI”, and “GUI...few offline tools available mostly work on any computer but generally require working knowledge of the... power of each tool they are interested in by comparing their past results to the designs suggested by...pattern at any edit distance. It won’t, however, compute any score other than the edit distance. Added functionality...

...division. These non-plasmid-containing bacteria can compete with and confound the goal of your experiment —...spectinomycin is the more stable and expensive antibiotic compared to streptomycin. Spectinomycin/streptomycin can...option! Otherwise, since it isn’t universally compatible with all bacteria used in research, it isn’t ...express the Tn5 element, but thankfully, most competent cells do not express this factor. Zeocin is handy...host/plasmid DNA during selection if it’s not completely bound up. While this likely occurs at a low rate...Stability Time Saving?  Works for multiple organisms? Compatible with most bacteria? No satellite colonies? ...

...immune system; and reconfiguring of the nuclear compartment, gene expression, and protein translation. Its...producer cells where there is E1 and E3 gene complementation. In target cells that are infected by the vector...virions) are not expressed. Note that replication-competent AdV vectors also exist and are used in certain...topic, which is that natural AdVs, replication-competent viruses with a recombinant genome, and adenoviral...higher than other viral vectors (tens of kilobases; compared to only 4.7 kb for AAV, 9 kb for retroviruses)...Tales: From the Cell Surface to the Nuclear Pore Complex. PLoS Pathog, 11(6), e1004821. https://doi.org/...

...Sharing data and community concerns AAV vectors are complex biological reagents; many factors, like storage...literature, scientists can use the Data Hub to compare different methods and vectors, and use this data...through word of mouth or old lab notebooks and computer files. If you asked your team members or colleagues...much unpublished AAV data do you have sitting in computers and notebooks right now?, I’m willing to bet the... rat CNS: AAV PHP.EB vector dose–response and comparison to AAV PHP.B. Gene Therapy, 25(5), 392–400. https..., C., & Flotte, T. R. (2015). Stability and compatibility of recombinant adeno-associated virus under ...

...just one or two recombination events, homemade competent cells of 107 CFU/μg are perfectly fine, yet performing...performing multiple modifications will require ultracompetent (109 CFU/μg) cells. Primer design Using specific...insertions, deletions, and point mutagenesis to complex assembly of multiple genes. Primer design for each...the forward primer by adding a short sequence complementary to the 5’ end of the reverse primer. Mutagenesis...efficiency of assembly decreases as the cloning complexity increases. The efficiency of recombination is...increased with greater homology, so performing more complex procedures can be aided by extending homologous...

...require a single-component nuclease to mediate cleavage rather than the multi-subunit complex employed by ...repair templates should remove the PAM sequence. Comparing Cpf1 and Cas9 on-target and off-target efficiency...lower than that of the widely used SpCas9 and comparable to SaCas9. As seen with Cas9 orthologs, Cpf1 ...sophisticated genome-wide analysis. At many of its computationally predicted off-target sites, Cpf1 does not mediate...sites, according to Kim et al. Kim et al. also compared the ratio of total off-target to on-target modification...

...editing is the potential for off-target effects. To compare the off-target effects of SpCas9 and SaCas9, Zhang...normal and liver injury markers were not increased compared to a control AAV-GFP. Not only did the AAV-SaCas9...had modest editing rates in HEK-293T cells when compared to the full-length SpCas9. In 2016, Chew et al...cleavage of HBB and CCR5 genes in human cells using compact expression cassettes. Sci Rep 5: . https://doi....Desmarais J, Nogales E, Doudna JA (2019) CasX enzymes comprise a distinct family of RNA-guided genome editors..., Nureki O (2014) Crystal Structure of Cas9 in Complex with Guide RNA and Target DNA. Cell 156:935–949...

... and/or are too expensive, time-consuming, and complex to use outside of standard laboratories. In the...step allowing for greater quantitation without compromising sensitivity. To detect multiple targets in ...signal of a single target. Csm6 can cleave ssRNA complementary to a crRNA of interest (Niewoehner and Jinek...with high sensitivity and specificity without compromising speed, ease of use, and portability. This method...molecular and clinical diagnostic applications. The company Mammoth Biosciences has been started based on DETECTR...ES, Koonin EV, Zhang F (2016) C2c2 is a single-component programmable RNA-guided RNA-targeting CRISPR effector...

...find a comparable library if it’s gone stale or we will need to update our code to be compatible with the...parts to our software, which has grown with the company. It would be easy to assign each developer to a.... Third party libraries are reusable software components that can be incorporated into software. You can...or they make significant changes that make it incompatible with our software. When this happens, we need...took us a total of two years, from planning to completion, to do this upgrade while continuing to add new...

...morpholinos. When injected into zygotes, morpholinos complementary to a target mRNA inhibit its translation either...observation unlocked novel research into genetic compensation, a previously unknown mechanism of gene regulation...established body plan including head, eyes, and tail. Compared to the opaque mouse embryo, where similar processes... been tracked using microscopy and advanced computational approaches (Keller et al., 2008). This microscopy-based...generation time and labor-intensive maintenance compared to invertebrate model systems, and their resistance...References El-Brolosy, Mohamed A., et al. "Genetic compensation triggered by mutant mRNA degradation." Nature...

...research proposal will distinguish between competing models. Comparing model A vs. B is more constructive than...about the time and resources required to feasibly accomplish the aims and clarify what type of aim you are...scaffolds with patient stem cells to generate compatible functional livers.” Why are you the best person...exist to solve the problem. What will you have accomplished in 5-10 years? You need to be able to describe...learned and/or now be possible to do? Research accomplishments are remembered for the problem solved, not ...

... assortment toxins to claim territory or kill competing microorganisms, but did you know bacteria also...subunit of DNA gyrase and trapping it in the cleaved complex. This results in DNA breakage and cell death. Conversely...toxin-antitoxin roles. Restriction modification systems are composed of restriction endonucleases and methyltransferases...populations to retain more of these plasmids as compared to those without the restriction modification ...described, the hok/sok systems consist of three components: Host killing (hok), a long-living toxin that...K. Burley. "Crystal structure of the MazE/MazF complex: molecular bases of antidote-toxin recognition....