...linear fashion. This implies that reducing the power 2-fold does not reduce photobleaching by half. How exactly...prolonged time). Other illumination strategies, such as 2-photon-excitation, selective plane illumination, TIRF...different ways. We describe a number of issues with some of the experimental designs used to make these...of Amsterdam. The previous post in this series described a practical approach to selecting a bright fluorescent... protein. Photobleaching is the irreversible destruction of a fluorophore under the influence of light...photobleach at some point. For live-cell imaging, it is desirable to have fluorescent proteins that are photostable...photoswitching (Kremers et al, 2009), which usually are undesired properties. In the ideal situation, a fluorescent...

...plasmid kit consists of 20 plasmids encoding 14 alpha, 2 beta, and 4 gamma subunits of the heterotrimeric G...activation via bioluminescence resonance energy transfer 2 (BRET2). Check out our blog post on GPCR signaling...new receptors were termed Designer Receptor Exclusively Activated by Designer Drugs (DREADDs) (Roth, 2016...What do smell, taste and sight have in common, besides being one of the five senses? GPCRs or G-protein-coupled...photons or odorants, to elicit downstream signaling cascades.  So let’s break down the name "G-protein coupled...then induce or inhibit intracellular signaling cascades as a response to the extracellular stimuli. Ligand...

...residues, which can be found throughout the antibody. 2) Endogenous cysteines, such as those that make up ...Detecting antigens by quantitative immuno-PCR. Nat Protoc 2:1918–1930. https://doi.org/10.1038/nprot.2007.267 ...we would be remiss not to at least mention. Oligonucleotides allow for sensitive detection of low abundance...strong protein-protein interactions with other peptides, like an Fc-binding domain (Figure 1).  ...Strong protein-protein interactions with other peptides. Created with BioRender.com.     Many biologists... conjugation. But hopefully, this introduction provides a good base from which to dive deeper!References...

...successfully regulated expression of channelrhodopsin-2, commonly used in optogenetics, opening up the possibility... Find plasmids from this publication at Addgene. 2. Tang, Jonathan C.Y., et al. “Cell type-specific manipulation...GFP-labeled cells. Once Tang and Cepko found a description of GFP-binding nanobodies, the project really...stable inside cells. Nanobodies binding GFP were designed in 2009. Subsequent work showed that nanobodies...green-red Cre-lox systems. T-DDOGs can also be designed with other DNA-binding domains, including the ...

...be decorated with proteins and remain functional, 2) break membranes outside of their natural context ...PubMed PMID: 3759909. PubMed Central PMCID: PMC213417. 2. Schrallhammer, M. et al. Tracing the role of R-bodies...of R bodies R bodies have been studied for many decades, and they were known to be resistant to detergents...

...Addgene gave to me: five methods for detecting SARS-CoV-2 using CRISPR.  On the sixth day of CRISPR, Addgene...#12DaysOfCRIPSR hashtag to share new CRISPR content designed to help you with your CRISPR experiments and to...CRISPR, Addgene gave to me: tips and tricks for designing gRNAs for CRISPR editing. On the fourth day of...

...anniversary! We've done so much in the past two (2!) decades that it's hard to summarize, but we wanted to...experience we're sharing through blogs, eBooks, videos, guides, protocols, and of course, the friendly folks at...

...this quick trick. Just flip, and press! Lab tip #2: Tube flick trick When combining reagents in the lab...distribution. Lab tip #3: Barcode everything Use barcodes and scanners to keep track of reagents in your...materials quickly and easily. Learn more about using barcodes. Check out our “Lab Tip” filter on the blog...

...11 and Cas13 are 1). non-specific RNA cleavage and 2). cell toxicity. Cas7-11 does not display collateral...Cpf1 is a single RNA-guided endonuclease of a class 2 CRISPR-Cas system. Cell, 163(3): 759-771 (2015). 10.1016...in one direction. Cas3 is thus not helpful for designer genome edits, but it is effective at wiping out...David, Chen, S., Janice, et. al. Programmed DNA destruction by miniature CRISPR-Cas14 enzymes. Science, 362...

...somewhere else (Fig. 2). Class II TEs have LTRs on both of their ends.    Figure 2: Overview of DNA... four major components: 1) a CRISPR RNA (crRNA), 2) four proteins (TniQ, Cas8, Cas7, Cas6) that forms ... sequence that moves around. This DNA sequence encodes the proteins the transposon needs for transposition...contain two genes: gag and pol. The pol polyprotein encodes the reverse transcriptase and integrase enzymes...ORFs) which often terminate with a poly(A). ORF2 encodes endonuclease and reverse transcriptase activities...preferred target site for integration is TA dinucleotides and it leaves behind the CAG DNA footprint from...encode reporter genes, mutagenic cassettes, or barcodes. When transposons are delivered to cells or a ...

...an internal promoter, and the desired gene (transfer vector plasmid), 2) the HIV-1 genome containing all... several protocols that have been described (protocol 1, protocol 2, protocol 3) to find the one that ...PubMed PMID: 3785217. PubMed Central PMCID: PMC367857. 2. Naldini, Luigi, et al. "In vivo gene delivery and...quantify viral RNA. All of these methods have been described in a previous Addgene blog Once you know your ...Miller, A. DUSTY, and C. A. R. O. L. Buttimore. "Redesign of retrovirus packaging cell lines to avoid recombination...

...due to the presence of additional helper sequences (2-3). As alluded to above, termination and polyadenylation...and translation processes as well.   Figure 2: The conserved eukaryotic polyadenylation signal directs...Plasmids designed to express genes in a given host cell type are generally broken down into two broad...post-transcriptional additional of multiple adenine (A) nucleotides to the tail of a messenger RNA transcript. The...structure of the hairpin-DNA complex is thought to destabilize the transcription complex, initiating cleavage...transcription of the template and initiating the desired cleavage event, although some engineered terminators...downstream elements. A high affinity terminator may be desired for multi-cistronic constructs where high termination...

...is funded have been well documented over the past 2 years (Alberts et al, PNAS 2014; Taylor, eLife, 2016...PMID: 24733905. Pubmed Central PMCID: PMC4000813. 2. Taylor, Justin Q., et al. “Avoiding a lost generation...for affecting change. On Friday, the symposium includes a panel discussion and keynote by former congressman...towards solutions. The 2015 Boston FoR meeting was designed to explore areas where further data is necessary...for students interested in leading the process despite the recent advance. Similarly, grad students throughout...development and implementation of new strategies designed to cope with current increases. These two rulings...

...from another within a fully stained sample. Figure 2 is an example of the emission spectra for two fluorophores...another during spectral unmixing.     Figure 2: The full emission spectra for BV421 and BV711 on ...positive and negative populations, Careful panel design In both conventional and spectral flow cytometry...indistinguishable. This tool is of particular value when designing a panel.     Figure 3: Similarity index...if markers are co-expressed in your cells when designing your panel. If you have two highly overlapping...

...that increase cancelled. Rounding out the remainder, 2% of postdocs who weren’t going to get a salary increase...with their plans, and 17 have cancelled their plans. 2 of those raising - the University of Illinois and ...the postdoctoral population which keeps growing despite a lack of available academic positions.   Many...

...studies have shown that the conditions Sotos-type 2 and Marshall Smith Syndrome are due to mutations in...accurate diagnosis of NFIX-related syndromes (Sotos-type 2 and Marshall-Smith) and could be expanded to NFIA-...guanidine moiety at the end of its side chain. Decades ago, other labs discovered that the in vitro functions...

... Zetsche et al., Nat Biotechnol. 2015 Feb 2;33(2):139-42. doi: 10.1038/nbt.3149. Light-inducible ...and on your favourite signalling pathways (Figure 2). They are all available now at Addgene. 1 Lungu...20;19(4):507-17. 10.1016/j.chembiol.2012.02.006. 2 Guntas et al., Proc Natl Acad Sci USA 2015 Jan 6; ...Nihongaki et al., Chemistry and Biology. 2015 Feb 19; 22(2):169-74. High efficiency cloning for enzyme screening...inducible, gene knockdown with shRNA or shRNA-miR30, (2) tamoxifen-inducible CreERT2 gene deletion, (3) simultaneous...different fluorescent proteins, 8 constitutive promoters, 2 includible promoters, 3 polyA terminators and various...of plasmids required for each input/output system; 2) removing all chemically inducible promoters; 3) improving...

... this blog post. I separate sgRNA design tools into database and de novo solutions. Database tools allow...community in order to succeed. With respect to de novo sgRNA design, I again separate it into two categories... tabular HTML formatted output. Surprisingly only 2 tools provide FASTA output. A few notable tools allow...Nature biotechnology(2014). PubMed PMID: 24880488. 2. Hsu, Patrick D., et al. "DNA targeting specificity...single-target design”, “multi-target design”, “off-target aware”, “high mismatch limit”, “approximate design”, “... “empirical design”, “single-PAM design”, and “multi-PAM design”. Trends: By the end of 2014, tools began...with the post-design process such as primer and plasmid design. Examples:  “multiplex design”, “multi-method...

...FRET signal back again. The Ting lab constructed 2 versions of this reporter to target the K9 (pcDNA3... 525.7570 (2015): 533-537. PubMed PMID: 26352475. 2. Bygren, Lars O., et al. "Change in paternal grandmothers... of the DNA with a high frequency of C and G nucleotides). The conversion of cytosine to 5-methylcytosine..., which binds selectively to lysine-methylated peptides. This construct is in the middle of a FRET pair...

...PMC2606057. 2. Chtanova, Tatyana, et al. "Dynamics of neutrophil migration in lymph nodes during infection... fluorescent proteins expressed in the specimen.  2. Fluorescence Activated Cell Sorter (FACs) A machine...photostability of your fluorescent protein when using 2-photon microscopy as this hasn't been well reported...their specificity or from the thymus to the lymph nodes. These methods gave researchers much more information...expressing cells. For example, by harvesting lymph nodes at different times after antigen challenge, scientists... cellular dynamics in lymphoid organs. In lymph nodes, for example, two-photon microscopy allowed scientists...extravasate from the bloodstream to invade lymph nodes and scan antigen presenting cells, but two-photon...