...cross-neutralization occurs in the P.1 and B.1.351 variants tested. Image from Garcia-Beltran et al., 2021 with permission...for the wild-type. However, variants such as the P.1 (Gamma variant) and the B.1.351 (Beta variant) were... tested at the time of this study. Figure 1: Neutralization levels against spike pseudovirus decreases...vaccines differed depending on the variants (Garcia-Beltran et al., 2021). Antibodies from individuals who ...represent lineages and variants that are actually transmitting out in the world” says Balazs. “By combining...quantified in terms of luminescence. Image from Garcia-Beltran et al., 2021 with permission.   Mutations ...with various pseudotyped virus. Image from Garcia-Beltran et al., 2021 with permission.   Difference ...

...directed against human transcription factors such as PAX7, PAX6, AP-2 alpha and ISLET-1. In addition, we distribute...Monoclonal Antibody Research Institute dedicated to: 1) developing new ways of generating antibodies, for...light chains and two heavy chains. The ends of the branches contain the antigen binding sites and are highly...

...2013) Analysis of Transduction Efficiency, Tropism and Axonal Transport of AAV Serotypes 1, 2, 5, 6, 8 and...(Figure 1). This results in one loxp site and one lox2272 site on either end of the transgene. Since loxp...cause of this spurious expression?   Figure 1.  Cre-recombinase binds to either pair of lox sites...recombination and can exhibit recombination levels as high as 1-3%. In light of this finding, we now include guidance...Vectors Pseudotyped with Viral Capsids from Serotypes 1, 2, and 5 Display Differential Efficiency and Cell...loxp pair, and flips the transgene into the correct orientation for transcription. Upon recombination one...flank a transgene (homologous pairs) or used different scrambled sequences to flank the transgenes (non-...

... and reproducibility of a study’s findings. Table 1: Biased Genotyping Options Technique Sequence Information...sequencing doesn’t tell the whole story Figure 1: Schematic representations of the indicated unbiased...types Must be verified with cell-based method IDLV 1% Cell-based Programmable, can detect DSBs in live ...magazine.scienceforthepeople.org/.     References 1. Fu, Yanfang, et al. "High-frequency off-target mutagenesis...next-generation sequencing." BMC genomics 15.1 (2014): 1. PubMed PMID: 25409780. PubMed Central PMCID: PMC4246457...between the edited strand and wild-type strand of the host DNA. When these strands hybridize, the nuclease...nuclease can detect strands with mismatches and cleave them. The results are then visualized using gel electrophoresis...

... cleaved out of the RNA transcript by endogenous processing enzymes (Figure 1). To ensure this tRNA processing... mRNA trans-splicing. A cis-splicing vector served as positive control (cis-ctrl). v1, vector 1; v2, vector...mRNA trans-splicing dual AAV vectors for (epi)genome editing and gene therapy. Nat Commun., 14(1), 6578...or nuclear expression of BFP2.     Figure 1: CROPseq-multi uses two sgRNAs with internal barcodes...RNA polymerase III transcript, the sgRNAs were encoded on the lentiviral minus strand in the 3’ LTR. These...HeLa cells transduced with SARS-CoV-2 nucleocapsid protein (Plasmid #141391-LV [+N]) or membrane protein ...high microglia transduction efficiency for the indicated ssAAV5s. Figure adapted from Serrano et al. 2023...

...nonstructural proteins 1 to 16, spike proteins, envelope small proteins, and membrane proteins. Although ...give your research more visibility.    Figure 1: Illustration of SARS-CoV-2 from Philippa Steinberg...Humana Press, pp 331–338 https://doi.org/10.1007/978-1-59745-181-9_23 Additional resources on the Addgene...glycoproteins and other proteins that require post-translational modification may not be easily expressed in ...sequencing as a first pass QC. The lab team manually transforms, innoculates, and performs DNA minipreps for ...

...reserve a small aliquot, split into two parts to (1) run a DNA gel to confirm fragment size and (2)  incubate...with a phenol-chloroform extraction.    Fig. 1: Schematic overview of ChIP. Image courtesy of Shengliu... let’s do a quick review. At this point you have (1) crosslinked your proteins of interest to any DNA ...Fragmenting  The next step is break the DNA into random, small pieces of roughly equal size, typically ...enzymatic digestion. Sonication provides a truly random digestion, but is harsher and requires more optimization...your protein of interest is a low abundance transcription factor or cofactor. In such cases, the gentler...

...overlap with the negative control population (Figure 1). Based on where the GFP- population ends, you can...total cells present in the gate.   Figure 1: Example of yes-no flow plot of the (negative) control...for a yes-no dot plot, like the one shown in Figure 1.  Figure 3: An example of a histogram plot ... Figure 2: (A) a smeary dot plot showing a range of antibody readouts. (B) A gate on the smeary dot...histogram plot for a smeary antibody readout. The orange peis the baseline expression of the protein of ...yes-no histogram plot shown previously. Here, the orange peak is a baseline expression of a protein while...

...dual-color control of neurons. Nature Communications, 12(1), 1–20. https://doi.org/10.1038/s41467-021-24759-5 Zhang...to consider when choosing one.     Figure 1: Example of an experimental optogenetic setup. A light... 21–51). Springer US. https://doi.org/10.1007/978-1-0716-0755-8_2 Lehtinen, K., Nokia, M. S., & Takala... 21–51). Springer US. https://doi.org/10.1007/978-1-0716-0755-8_2 Boyden, E. S., Zhang, F., Bamberg, E... charged ions to rapidly pass through the cell membrane and initiate an action potential - a very useful...and close when exposed to light and change the membrane potential. OptoXRs are modified GPCRs. When exposed...downstream signaling pathways that can change both the membrane potential and a host of other cellular functions...

... emailed submission) in the Deposit menu: Figure 1: Begin the deposit process by clicking "Submit Online...cases Please contact us at [email protected] or +1 (617)-ADDGENE (233-4363) if your deposit falls into...Addgene?" or contact us at [email protected] or +1 (617)-ADDGENE (233-4363) with additional questions...strain. Please contact us at [email protected] or +1 (617)-ADDGENE (233-4363) if you’d like to distribute...page so that any data you enter is not lost.   Step 1: Sequences, Maps, and Files Please provide any full...a 1.5 mL microfuge tube at a concentration of 0.1–1 µg/µL (or bacterial streaks, if you prefer). If you...number of unique plasmids in a pooled library can range from a few hundred to millions. Pooled libraries...

...control exactly in which locus your transgene ends up (1): Random insertion has the advantage that you...pound symbol”. References 1. J. R. Bateman, et al. Site-Specific Transformation of Drosophila via PhiC31... you’d like to use to generate your new fly line: 1. Where would you like the gene to be incorporated ...you need to combine multiple transgenes in one fly, having the transgenes in different loci allows for...use? Random insertions take longer because you need to determine in which chromosome your transgene has...brief introduction as to how you can engineer new transgenic flies to study your favorite gene (YFG).  Sometimes... is thrillingly new, you might have to make a transgenic fly in order to study it. The process is fairly...

...indicates the presence of a multimer.   Fig. 1: The monomer of Plasmid 12259: pMD2.G (depicted on...plasmid sequencing services using long-read sequencing (1-25 kb), such as Oxford Nanopore sequencing or PacBio...10017-26. doi: 10.1074/jbc.M110.176636. Epub 2011 Feb 1. PMID: 21285356; PMCID: PMC3060453. Bazaral M, Helinski...multiple circular DNA forms of colicinogenic factor E-1 from Proteus mirabilis. Biochemistry. 1968 Oct;7(10...Methods Mol Biol. 2009;582:11-25. doi: 10.1007/978-1-60761-340-4_2. PMID: 19763938. Maucksch C, Bohla A...size, multimers may exhibit reduced transformation and transfection efficiency compared to the monomeric... Elfinger M, Hartl D, Rudolph C. Transgene expression of transfected supercoiled plasmid DNA concatemers...

... tissue. References 1. Aschauer DF, Kreuz S, Rumpel S. Analysis of transduction efficiency, tropism and... and axonal transport of AAV serotypes 1, 2, 5, 6, 8 and 9 in the mouse brain. PLoS One. 2013 Sep 27;8...M. Human synapsin 1 gene promoter confers highly neuron-specific long-term transgene expression from an...AAV5, AAV8) enable different patterns of transduction and transgene expression across different cell types...expressed from your cell line of choice after transduction with this virus. While various Cas9 mutants ...classic Cas9 nuclease, which introduces double stranded DNA breaks, can be expressed from lentiCas9-Blast...single stable Cas9-expressing cell line and then transduce this line with lentiviruses expressing various...

...-HA frankenbodies include mEGFP, mCherry, and HaloTag. Figure 1: (a) Anti-FLAG frankenbody (FB)...Comm. 2019. https://doi.org/10.1038/s41467-019-10846-1.   Optimized genetic screening technique using Cas12a... to Cas9’s larger expression requirements (Figure 1), but Cas12a has generally been underutilized in genetic...Here's what you'll find in this post: Anti-FLAG Frankenbodies for modular imaging of cellular targets Optimized...mammalian genome regulation and editing Anti-FLAG Frankenbodies for modular imaging of cellular targets by: ...: Mike Lacy Adding to their set of anti-HA frankenbodies (Zhao et al. 2019), Tim Stasevich and Hiroshi... have recently published a set of anti-FLAG frankenbodies, a flexible, modular tool for labeling. Here...

...unleashes its cargo – its own genome.   Fig. 1: Viral particle infection into a host cell. Image ...Vector Resources at Addgene! References and Resources 1. Roe T, et al. “Integration of murine leukemia virus...nuclear import of human immunodeficiency virus type 1 preintegration complexes.” Proc. Natl. Acad. Sci. ...one they have a high transduction efficiency and can effectively infect a wide range of cell types that ...used to achieve transient, high expression of the relevant cargo without the fear of random genomic integration... Packaging Capacity (>8kb) High Transduction Efficiency Transient Gene Expression High Immunogenecity...viral envelope, which fuses with the target cell’s membrane, allowing the viral particle access into the cell...

...available from their original sources. Figure 1: Biological repositories that distribute mouse strains... from Reproducibility for Everyone. Case study 1: Cell lines Many of the reagents used to investigate...observational study. The Lancet Microbe 1:e14–e23 . https://doi.org/10.1016/s2666-5247(20)30004-5 McCray...scientific community. Addgene was awarded a Fast Grant to ensure that the scientific community will continue...-2. The resurgence in popularity of the hACE2 transgenic mouse strain, for example, is sustained by the...University of Iowa (McCray et al., 2006), the hACE2 transgenic mice were designed after it was discovered that...Deposits of new reagents, policies from journals and granting agencies requiring materials to be deposited into...

...s pLKO.1 protocol. Pro-tip: this plasmid grows more slowly than standard plasmids. Find pLKO.1 - TRC cloning...experiments.  Find the scrambled shRNA vector. pLKO.1 - TRC cloning vector - This vector from the David ... different cell types so it is useful in a wide range of applications. This plasmid was the top requested...pSpCas9(BB)). The 2A-GFP allows for screening of transfected cells. Find pSpCas9(BB)-2A-GFP (PX458). lentiCRISPR...lentiCRISPR v2 - This 3rd generation lentiviral transfer vector also from the Zhang lab is used to deliver...David Root lab is a 3rd generation lentiviral transfer plasmid for cloning and expressing new shRNA sequences...the necessary elements for packaging, reverse transcription, and integration needed for the production of...

... the samples stored in our lentivirus tubes (Fig. 1). However, once thawed, there was a substantial reduction...in the pH of samples stored in our AAV tubes (Fig. 1). It’s important to note that the change in pH only...using the thawed virus within 24 hours. References 1. Murphy BM, Swarts S, Mueller BM, van der Geer P, ... However, the pH changes in our solutions are transient and return to normal once the tube is opened and...restored. We have no evidence to suggest that the transient change in pH affects AAV function. Furthermore...Furthermore, another study tested AAV infectivity after a range of pH exposures. They showed that AAV infectivity...MC, Fitchmun MI. Protein instability following transport or storage on dry ice. Nat Methods. 2013 Apr;10...

...digital) signal at the end of the reaction (Figure 1). Partitions that did not contain any target DNA at...integrated through homology-directed repair (HDR) (1), or indel mutations resulting from non-homologous...Follow him on Twitter @AnotherLabRat.     References 1. Miyaoka, Y. et al. Isolation of single-base genome-edited...edit. Since exploitation of NHEJ to generate translational reading frame-altering indels for “functional... an unedited site distal tothe predicted double strand break, and a NHEJ/ “drop-off” probe designed to...to bind directly at the predicted double strand break site (Figure 2A). The single molecule resolution...PubMed PMID: 26914317. 4. Mock, U. et al. mRNA transfection of a novel TAL effector nuclease (TALEN) facilitates...

...flanked by ~50-150 bp transposon end sequences (R and L ends).  Figure 1: (A) Components involved...CRISPR-associated Transposase) by the Zhang group. Mechanism of CRISPR-transposons One of the CRISPR-transposon systems...DNA transposons have been hindered by their limited programmability: depending on the transposases involved...-guided transposition. By natively combining the DNA integration capabilities of transposases and the ...crRNA.  Three transposase proteins (TnsA, TnsB, TnsC). The donor DNA (aka mini-transposon), which contains... each type of CRISPR-Transposon system. (B) Mechanism of RNA-guided transposition in type I-F INTEGRATE.... Separately, TnsABC forms a transposase complex with the mini-transposon, excises it from the donor molecule...

...skeletal muscle contraction.   References 1. Degorce, François, et al. "HTRF: a technology tailored for..."Förster resonance energy transfer measurements of ryanodine receptor type 1 structure using a novel site-specific...standard for genetically-encoded FRET donors (Fig. 1). Scores of FP variants have been created, thereby...with finesse using tRNA suppression technology (Fig. 1) (Dumas, Lercher, Spicer, & Davis, 2015). By using...orthogonal labeling strategies are presented (Fig. 1) which can be carried out using Addgene plasmids. ...they cannot cross cell membranes, so they are best used either with plasma membrane proteins (such as GPCRs... minimum energy transfer values you can expect, thereby establishing the dynamic range of your FRET assay...

... experimented with a group mentoring format where 1 mentor met with a group of mentees to get more “bang...The groups in these programs typically consist of 1-2 mentors and 3-5 mentees who meet together for an...get together. If you all work at the same place, a 1-2 hour lunch on a regular schedule might work. If ...meeting at both the Fox Chase Cancer Center and Brandeis University. 5 easy steps to forming your own peer... of people who are all interested in making a transition. Schedule your first meeting and get organized... your successes and support each other as you transition to the next stage in your careers! Stay in touch...

...effective recovery of knock-ins, but did result in 1-2 kilobases of additional sequence being introduced...facilitating recovery of edited animals. Figure 1: In the background are 504 restriction digests of ...selection for repair of a temperature-sensitive pha-1 mutation significantly enriches for knock-in of 2x... 3xFLAG epitopes into other, non-linked loci; pha-1(e2123) mutant worms are perfectly viable at 15 ºC,... repair pathway. Reagents required to perform pha-1 co-conversion are available through Addgene. In 2019... technologies have transformed the palette of experiments possible in a wide range of organisms and cell...genomic locus (CRISPR-ChAP-MS) could further transform the range of experiments imaginable in C. elegans. ...

... levels. That is, if transcription factor 1 controls expression of transcription factor 2, which directly...by modulating the induction of transcription factors 1 and 2. See Aranda-Díaz et al. for more information...difficult-to-manipulate primary cells, achieving knockdown within 1-2 hr of reagent delivery. TRIM-Away is suitable for...expression, Aranda-Díaz et al transformed yeast with both a GAL4/estradiol controlled transcription factor ... a broad pH range. The four biometric probes successfully targeted endosomes under a range of pH conditions...ligand binding domains and the MSN2 transactivation domain. Transcription factor activation via the appropriate...progesterone controlled transcription factor as well as reporters specific to each transcription factor. They then...

... help improve the transport of protein of interest the membrane.   Figure 1: Electron microscope...proportion were found on the plasma membrane (top panel in Fig. 1). Of course, this was problematic, because...expression of hM4Di in plasma membranes in both species (bottom panel in Fig. 1). Our results indicate that... the transgene of interest. In our studies, mCherry interfered with the transport to the membrane of the...the hM4Di might improve the transport of this DREADD to the plasma membrane. The haemagglutinin (HA) tag...the expression of the transgene of interest and its localization in the membrane. The lesson we learned... the plasma membrane. Note that the use of the HA tag significantly improves the transport of hM4Di to...

... Figure 1: Strand separation and target DNA binding to the Cas9 nuclease. Stable strand separation ...by 2 sets of interactions : 1. Interactions between the non-target strand and a positively charged groove... improvements in genome engineering! References 1. Slaymaker, Ian M., et al. "Rationally engineered ...increases when target DNA strand separation is stabilized (2,3). Stable strand separation is maintained...and therefore destabilize basal strand separation. This decreased strand separation combined with the weak...the non-target strand and the HNH/RuvC groove, and interactions between the target strand and the gRNA....nuclease domains 2. Interactions between the target strand and the gRNA (see figure below) Because off-target...

...Figure 1: The Addgene Requests Dashboard   The dashboard will display the following items (Fig. 1): ...depositor, but it can also be valuable data to share in grant proposals or to demonstrate impact in annual reports...

...neuron which generates an action potential (Figure 1). This light-induced excitation can take place in ...channelrhodopsin activation to a small volume of brain tissue (~1 mm3). Current channelrhodopsins also need high-intensity...fiber-optic cables into the brain. Figure 1: With no blue light, the channelrhodopsin remains ... that determine membrane expression and plasma membrane localization of transmembrane proteins, like rhodopsins...capable of broad transduction of the nervous system which eliminates the need for intracranial injections. ... to perform in vivo optogenetic experiments. Intracranial injections of AAV are commonly used to deliver...channelrhodopsin-based optogenetics minimally-invasive, Frances Arnold’s lab and Viviana Gradinaru’s lab used machine...

...Collection Fluorescent tagging strategy Figure 1: Gene editing is the addition of a useful coding sequence...plasmid design strategy. A donor plasmid contains 1 kb homology arms matching the gene of interest, a ...Institute website at alleninstitute.org. References 1. Roberts, Brock, et al. "Systematic gene tagging using... copy. The coding sequence for GFP is transcribed and translated along with the gene, producing both a...exon of the gene to ensure it would be transcribed and translated. For an N-terminally tagged protein, ...destroyed by CRISPR/Cas9 during transfection. Making the double strand break and introducing the tag through...base pairs on each side, in fact. Later, when we transfect the cells, these large regions of homology enable...

...Popular gamma-Retroviral Transfer Vectors   Expressing your gene of interest pMKO.1 GFP (Plasmid #10676) ...GFP expression.  Cloning and expressing RNAi pMKO.1 puro (Plasmid #8452) RNA interference (RNAi) is an...information and a detailed protocol on how to use the pLKO.1 vector can be found here. Cre-Lox technology Puro....split-vector systems’ by separating viral genes and transgene expression across several plasmids. The most commonly...separate envelope and packaging plasmids as well as transfer plasmids. This concept ensures safe handling and...Gamma-retroviral vectors have a relatively high transduction efficiency, but in contrast to lentiviral vectors... are very versatile tools as they are able to transduce dividing and non-dividing cells. More detailed...

... biosensor, so that the (1) binding of calcium, (2) allosteric rearrangements of the sensor, and (3) subsequent... to a red fluorescent state only by simultaneous (1) user-controlled illumination with violet light and...fluorescent indicators. Nature protocols. 2006 Aug;1(3):1057-65. Resources on Addgene.org Addgene’s AAV...your expected range. For example, calcium in the ER lumen reaches the sub-millimolar range, much higher...are used to monitor calcium concentrations and transients in living cells and organisms. Unlike chemical...sensors available that will localize at the plasma membrane. GCaMP-X is a nucleus-targeted GCaMP6 with an ...an extra apoCaM-binding motif to prevent aberrant binding of the biosensor to endogenous calmodulin. Multiplexing...

...the other (Sandomenico et al., 2020). Figure 1: Comparison between the IgG antibody and scFv. ...intensity of a tagged protein. SunTag has two components: 1) a protein of interest that’s tagged with 10-24 copies...Application. Clinical and Developmental Immunology 2012:1–15 . https://doi.org/10.1155/2012/980250  Bates A,...without disulfide bonds, made by molecular evolution 1 1Edited by I. A. Wilson. Journal of Molecular Biology... the CAR facilitates signal transduction and release of cytotoxic granules from the T cell. When a CAR...., 2012, Bates and Power., 2019): rapid blood clearance, which is useful for imaging applications; better...small size (Bates and Power., 2019). Their rapid clearance from blood can be a drawback for therapeutic applications...

...domain (Figure 1).  Figure 1: Examples of sites on antibodies used for conjugation. 1) Endogenous ...microscopy, flow cytometry, or spectrophotometry. The range of fluorophores available for antibody conjugation... choice for ELISAs.  Biotin Biotin is used in a range of antibody-based assays. Biotin itself is not visible...Endogenous carbohydrates added to antibodies post-translationally. 4) Modifications made to antibodies, such ...commercially conjugated antibodies available, that never guarantees the antibody you need will be conjugated, or ...Stephenson W, et al (2017) Simultaneous epitope and transcriptome measurement in single cells. Nat Methods 14:...

...current state (Green when off, dark when on). Figure 1: Photoswitchable MEK1 (psMEK1). Is it possible to ...Below are a few examples demonstrated in Zhou et al. 1. Testing kinase inhibitors Zhou et al examined the...the protein and pdDronpa are preserved. References 1. Zhou, Xin X., Linlin Z. Fan, Pengpeng Li, Kang Shen...Signal transduction pathways are a lot like cell phone networks. Protein kinases deliver messages to ..., and how long their signals last all impact transduction of the message. To study signaling pathways,... game of telephone, often the signal must be transmitted by intermediate messengers. Optical control of...signaling by using psMEK1 and an ERK kinase translocation reporter with a mRuby2 fluorescent reporter ...

...glassware should be treated with a DEPC solution for 1 hour, and autoclaved to remove residual DEPC. Alternatively...more large, expensive ultracentrifuge.  Figure 1: An outline of the different steps in RNA extraction...extraction: twenty-something years on. Nature Protocols 1:581–585. https://doi.org/10.1038/nprot.2006.83 Additional...expense, and less of being left with a bunch of random solutions when all the spin columns run out. In... inherently not as stable as DNA- it is single stranded and its ribose groups are susceptible to hydrolysis...effectively isolate intact RNA, a fast, strong protein denaturant would be required- something that broke down ...Chirgwin and colleagues showed that a strong protein denaturant, guanidinium thiocyanate, did just this (Chirgwin...

... of the biotin-avidin interaction   Figure 1: Biotin is enriched in egg yolk while its binding ... substrate (Holden and Cremer, 2003). References 1. Chapman-Smith, A., & Cronan, J. E. “Molecular Biology...matrices.” Journal of Nanobiotechnology 13.1 (2015): 1–14. PubMed PMID: 25980573. PubMed Central PMCID: PMC4461904...detection by northern blotting.” Rice 7.1 (2014): 1–7. PubMed PMID: 26224555. PubMed Central PMCID: PMC4884002...purification of tagged transcription factors in mammalian cells and transgenic mice.” PNAS 100.13 (2003...and decarboxylases. These enzymes catalyze the transfer of carboxyl groups to organic acids to produce...lipogenesis, amino acid metabolism and energy transduction. Biotinylation is the general process by which...

... requires selection. These two steps are (Figure 1): The initial plasmid integration step (the so-called...antibiotic resistance marker from the vector (abR, Figure 1). The resolution step (“double crossover”) which leads... loss of a specific phenotype (using sacB, Figure 1, further discussed below).  Counter-selectable marker...Current protocols in molecular biology 106.1 (2014): 1-16. PubMed PMID: 24733238. Additional resources on...strong transcriptional terminator BBa_B1002 (from IGEM) upstream of the MCS to reduce transcriptional readthrough...rely on exogenous enzymes, require multiple transformation and plasmid curing steps, and can generate ...worked too. Rhamnose induction relies on the transcriptional activator rhaS. To allow manipulation of bacteria...

... employing HDR. Ma et al. moved forward with gRNA 1 to conduct microinjection experiments in S phase zygotes...instead from the mother’s wild type allele (Figure 1). 72.4% of embryos carried two wild-type copies of...proceeded through NHEJ rather than HDR. Figure 1: Homology-directed repair in targeted zygotes proceeds...the embryos underwent repair not from the single-stranded oligonucleotide (ssODN) template supplied by Ma...maternal allele rather than the supplied single-stranded oligonucleotide (ssODN) template. Embryos also...off-target effects, but this advantage likely won’t transfer to all genes we’d like to target. In addition,...

...succumb to the toxicity of CcdB.   Figure 1: Image from Bernard, P., et al. showing the pKIL 18...submit a guest blog entry of your own! References 1. Bernard, P. “Positive Selection of Recombinant DNA... plasmid ccdB killer gene”. Gene. 1994 Oct 11;148(1):71-4. PubMed PMID: 7926841. 4. Bernard, P., et al...poison, locking up DNA gyrase with broken double stranded DNA and ultimately causing cell death. ccdA, another...gene in frame with an MCS. E. coli that were transformed with the empty vectors expressed the ccdB gene... that ccdB Survival™ can be more difficult to transform, depending upon the specific plasmids being used...

... two of the remaining viral proteins. Only Nsp11 ran bigger than expected, and Orf7b gave a lot of background...received so many requests (175 and counting) that we ran out of FedEx supplies at one point and had to go ...faster. Years of science, done in weeks Figure 1: Sending out 80 FedEx envelopes in a single day --...right) from the University of California, San Francisco. Manon Eckhardt and Melanie Brewer are on the ...