gfp   35

Influence of cell growth conditions and medium composition on EGFP photostability in live cells | BioTechniques
Interesting - EGFP may be up to 8 times more stable in F12 compared to DMEM....

Photostability is a key characteristic of fluorescent proteins. It was recently demonstrated that green fluorescent protein (GFP) photobleaching in live cells can be suppressed by changes in medium composition. Here we show that Ham's F12 medium provides very high enhanced GFP (EGFP) photostability during fluorescence microscopy of live cells. This property of Ham's F12 medium is associated with decreased concentrations of riboflavin and pyridoxine, and increased concentrations of FeSO4, cyanocobalamine, lipoic acid, hypoxanthine, and thymidine compared with DMEM. We also found that the rate of EGFP photobleaching strongly depends on cell growth conditions such as cell density and the concentration of serum. We conclude that both imaging medium composition and the physiological state of the cells can strongly affect the photostability of fluorescent proteins. Thus, accurate comparison of the photostabilities of fluorescent proteins should be performed only in side-by-side analysis in identical cell growth conditions and media.
GFP  egfp  photobleaching 
4 weeks ago by Segalllab
Can We Trust in HDLC?
in spite of the theoretical error detecting capability of its CRC, the actual degree of data integrity provided by HDLC is quite low.

The paper gives a quantitative assessment of HDLC's deficiencies and of their reasons, paying particular attention to actual applications of the HDLC family of standards.

Finally, we look at some strategies that have been suggested to allow the use of HDLC in the most demanding applications.
networking  network  atm  frame  relay  ax.25  GFP  generic  framing  protocol 
september 2018 by kc5tja
EGF receptor signaling, phosphorylation, ubiquitylation and endocytosis in tumors in vivo | eLife
Interesting estimates of EGFR ligand concentration in tumors and also an argument that ERK signaling is sensitive to these low concentrations while other pathways require higher ligand concentrations

"We labeled endogenous EGFR with GFP by genome-editing of human oral squamous cell carcinoma cells, which were used to examine EGFR-GFP behavior in mouse tumor xenografts in vivo. Intravital multiphoton imaging, confocal imaging of cryosections and biochemical analysis revealed that localization and trafficking patterns, as well as levels of phosphorylation and ubiquitylation of EGFR in tumors in vivo closely resemble patterns and levels observed in the same cells treated with 20–200 pM EGF in vitro. Consistent with the prediction of low ligand concentrations in tumors, EGFR endocytosis was kinase-dependent and blocked by inhibitors of clathrin-mediated internalization; and EGFR activity was insensitive to Cbl overexpression. Collectively, our data suggest that a small pool of active EGFRs is sufficient to drive tumorigenesis by signaling primarily through the Ras-MAPK pathway.
EGFR  HNSCC  468  ERK  GFP  intravital_imaging 
april 2018 by Segalllab
The world's first glow-in-the-dark frog found in Argentina
n the case of Hypsiboas punctatus, we found that under twilight-nocturnal conditions, between 18% and 30% of all the light (photons) emanating from the frog’s skin were florescent. That’s a substantial proportion, enough to add significant fluorescence to the typical green (in daylight) colouration of the frog, enhancing its visibility.

Finding fluorescence in a land animal is particularly interesting because it has been generally considered irrelevant but for its presence in some insects (spiders, scorpions, beetles, butterflies, moths, dragonflies, millipedes) and in two avian species, parrots and parrotlets. In parrotlets, differences in feather fluorescence between sexes have been found to serve a function in mating and attraction.

With the polka-dot tree frog, we expect that its fluorescence plays a role in inter-species visual communication (because it matches the sensitivity of the frogs’ eyes photoreceptors for blue and green). We do not believe that it has any relevance to mating, as florescence does not seem to differ between females and males.
frogs  bioluminescence  Hypsiboas-punctatus  fluorescence  GFP 
march 2017 by zzkt
Yes, Another Science Blog: My Life as a PhD Scientist – You Should Know Why Science Will Fail
> Douglas Prasher got the shortest end of the stick. He should have gotten the Nobel Prize. He got the opposite. Prasher cloned and sequenced the gene for Green Fluorescent Protein (GFP). And Prasher was the first to propose that GFP could be used as a tracer molecule. He wrote a grant detailing how GFP could be used as a reporter to measure the levels of gene expression and track the localization of proteins in cells. Every geneticist and molecular biologist alive today uses GFP assays in their research. GFP revolutionized the field and allowed scientists to make rapid leaps forward. Not surprisingly, the work for GFP received the Nobel Prize. Only, Prasher didn’t win it. You see, that grant he wrote about GFP never got funded. The reviewers of the grant thought his ideas were crazy. Without funding, Prasher didn’t get tenure. He had to close his lab. He gave his GFP samples and ideas to his fellow colleagues. He knew how important GFP was, and he didn’t want it to be lost. With no funding, Prasher was forced out of science altogether. He became a shuttle bus driver for a car dealership.
douglas_prashner  gfp  science  career  post_mdphd 
january 2017 by porejide
Manipulation of cellular light from green fluorescent protein by a femtosecond laser : Nature Photonics : Nature Publishing Group
possible mechanism of photobleaching/cell death by multiphoton which involves CRAC1 induced Ca influx leading to mitochondrial release of ROS.
stim1  crac  ORAI1  gfp  photobleaching  multiphoton 
december 2012 by Segalllab
A new glow for electron microscopy
The glowing green molecule known as green fluorescent protein (GFP) has revolutionized molecular biology. When GFP is attached to a particular protein inside a cell, scientists can easily identify and locate it using fluorescence microscopy. However, GFP can’t be used with electron microscopy, which offers much higher resolution than fluorescence microscopy.
gfp  microscopy 
november 2012 by djswagerman

related tags

468  aequorea_victoria  aequorin  algae  all  artificial  atm  ax.25  bacterialsensors  bioclock  biocompatible  biolaser  biological  biology  bioluminescence  biomimicry  blue  business  career  cell  central_dogma  chemistry  conversion  cost  crac  cream  dark  database  delicious  discovery  diybio  douglas_prashner  dye  ecoli  education  egfp  egfr  energy  erk  external  flash  flourescent  fluorescence  fluorescent  fluorophore  fly  frame  framing  frogs  general  generator  generic  genetics  glow  green  greenfluorescentprotein  guide  hnscc  hypsiboas-punctatus  ice  imaging  immune  in  intravital_imaging  jellyfish  journal_club  lab  laser  lecture  light  living  lizandra  localisation  low  lung_colonization  materials  metastasis  microbiology  microscopy  mirna  multiphoton  nagasaki  natural  network  networking  nobel_prize  optics  orai1  pcr  photobleaching  photosynthesis  post_mdphd  power  protein  protocol  pumped  pymt  receptionist  relay  research  ring  sal  science  sensitized  sensors  shimomura  single  solar  solid  spectrum  state  stim1  substrate  synbio  syntheticbiology  tatiana  technology  the  tutorial  ultraviolet  uv  virtual_assistant  yale  yeast 

Copy this bookmark: