Enhanced Multiplexing of Immunofluorescence Microscopy Using a Long‐Stokes‐Shift Fluorophore

2021 ◽  
Vol 1 (8) ◽  
Author(s):  
Sydney J. Reitz ◽  
Andrew D. Sauerbeck ◽  
Terrance T. Kummer
Keyword(s):  
Immunofluorescence Microscopy ◽  
Stokes Shift

The application of video-enhanced constrast/differential interference constrast microscopy in conjunction with whole mount electron microscopy to the study of organelle transport

1988 ◽  
Vol 46 ◽  
pp. 66-67
Author(s):  
J. H. Hayden
Keyword(s):  
Electron Microscopy ◽  
Rana Pipiens ◽  
Silver Film ◽  
Immunofluorescence Microscopy ◽  
Organelle Transport ◽  
Linear Element ◽  
Whole Mount ◽  
Carbon Coated ◽  
Linear Elements ◽  
Dic Microscopy

In a previous study, Allen video-enhanced constrast/differential interference constrast (AVEC-DIC) microscopy was used in conjunction with immunofluorescence microscopy to demonstrate that organelles and vesicle move in either direction along linear elements composed of microtubules. However, this study was limited in that the number of microtubules making up a linear element could not be determined. To overcome this limitation, we have used AVEC-DIC microscopy in conjunction with whole mount electron microscopy.Keratocytes from Rana pipiens were grown on glass coverslips as described elsewhere. Gold London Finder grids were Formvar- and carbon coated, and sterilized by exposure to ultraviolet light. It is important to select a Formvar film that gives a grey reflection when it is floated on water. A silver film is too thick and will detract from the image in the light microscope.

Intrinsic doping limit and defect-assisted luminescence in Cs4PbBr6

2019 ◽  
Author(s):  
Young-Kwang Jung ◽  
Joaquin Calbo ◽  
Ji-Sang Park ◽  
Lucy D. Wahlley ◽  
Sunghyun Kim ◽  
...  
Keyword(s):  
First Principles ◽  
Room Temperature ◽  
Stokes Shift ◽  
Green Luminescence ◽  
Counter Ions ◽  
Self Consistent ◽  
Deep Ultraviolet ◽  
Halide Perovskite ◽  
Related Compounds ◽  
Level Analysis

Cs<sub>4</sub>PbBr<sub>6 </sub>is a member of the halide perovskite family that is built from isolated (zero-dimensional) PbBr<sub>6</sub><sup>4-</sup> octahedra with Cs<sup>+</sup> counter ions. The material exhibits anomalous optoelectronic properties: optical absorption and weak emission in the deep ultraviolet (310 - 375 nm) with efficient luminescence in the green region (~ 540 nm). Several hypotheses have been proposed to explain the giant Stokes shift including: (i) phase impurities; (ii) self-trapped exciton; (iii) defect emission. We explore, using first-principles theory and self-consistent Fermi level analysis, the unusual defect chemistry and physics of Cs<sub>4</sub>PbBr<sub>6</sub>. We find a heavily compensated system where the room-temperature carrier concentrations (< 10<sup>9</sup> cm<sup>-3</sup>) are more than one million times lower than the defect concentrations. We show that the low-energy Br-on-Cs antisite results in the formation of a polybromide (Br<sub>3</sub>) species that can exist in a range of charge states. We further demonstrate from excited-state calculations that tribromide moieties are photoresponsive and can contribute to the observed green luminescence. Photoactivity of polyhalide molecules is expected to be present in other halide perovskite-related compounds where they can influence light absorption and emission. <br>

Intrinsic doping limit and defect-assisted luminescence in Cs4PbBr6

2019 ◽  
Author(s):  
Young-Kwang Jung ◽  
Joaquin Calbo ◽  
Ji-Sang Park ◽  
Lucy D. Wahlley ◽  
Sunghyun Kim ◽  
...  
Keyword(s):  
First Principles ◽  
Room Temperature ◽  
Stokes Shift ◽  
Green Luminescence ◽  
Counter Ions ◽  
Self Consistent ◽  
Deep Ultraviolet ◽  
Halide Perovskite ◽  
Related Compounds ◽  
Level Analysis

Cs<sub>4</sub>PbBr<sub>6 </sub>is a member of the halide perovskite family that is built from isolated (zero-dimensional) PbBr<sub>6</sub><sup>4-</sup> octahedra with Cs<sup>+</sup> counter ions. The material exhibits anomalous optoelectronic properties: optical absorption and weak emission in the deep ultraviolet (310 - 375 nm) with efficient luminescence in the green region (~ 540 nm). Several hypotheses have been proposed to explain the giant Stokes shift including: (i) phase impurities; (ii) self-trapped exciton; (iii) defect emission. We explore, using first-principles theory and self-consistent Fermi level analysis, the unusual defect chemistry and physics of Cs<sub>4</sub>PbBr<sub>6</sub>. We find a heavily compensated system where the room-temperature carrier concentrations (< 10<sup>9</sup> cm<sup>-3</sup>) are more than one million times lower than the defect concentrations. We show that the low-energy Br-on-Cs antisite results in the formation of a polybromide (Br<sub>3</sub>) species that can exist in a range of charge states. We further demonstrate from excited-state calculations that tribromide moieties are photoresponsive and can contribute to the observed green luminescence. Photoactivity of polyhalide molecules is expected to be present in other halide perovskite-related compounds where they can influence light absorption and emission. <br>

Antiproliferative Effects of Ocimum basilicum Methanolic Extract and Fractions, Oleanolic Acid and 3-epi-Ursolic Acid

2020 ◽  
Vol 6 (2) ◽  
pp. 134-146 ◽  
Author(s):  
Kehkashan Arshad Qamar ◽  
Ahsana Dar Farooq ◽  
Bina S. Siddiqui ◽  
Nurul Kabir ◽  
Sabira Begum
Keyword(s):  
Ursolic Acid ◽  
Oleanolic Acid ◽  
Mitotic Spindle ◽  
Immunofluorescence Microscopy ◽  
Methanolic Extract ◽  
Folk Medicine ◽  
Ocimum Basilicum ◽  
Antiproliferative Effects ◽  
Ancient Times ◽  
Mcf 7

Aims: The aim of the current study was to identify active compound(s) responsible for the antiproliferative effects of O. basilicum and explore their underlying mechanism/s. Background: Plants have been the source of medicines for the treatment of various diseases since ancient times. Ocimum basilicum (Sweet Basil, Bobai Tulsi) has been used in the folk medicine for the treatment of human liver, spleen and stomach cancers. Background: Plants have been the source of medicines for the treatment of various diseases since ancient times. Ocimum basilicum (Sweet Basil, Bobai Tulsi) has been used in the folk medicine for the treatment of human liver, spleen and stomach cancers. Objective: To emphasize the importance of O. basilicum as a potential novel non-toxic alternative to the conventional anticancer therapy. Method: O. basilicum (aerial parts) methanolic extract and fractions were screened against HT-144, MCF-7, NCI-H460 and SF-268 human cancer cell lines using sulforhodamine B assay. The more active Petroleum Ether Insoluble (PEI) fraction was fractionated into six sub-fractions (OB-1 to OB-6). Four pure compounds (3-O-methyl ursolic acid, oleanolic acid, 3-epi-ursolic acid and ursolic acid) were isolated from the more potent sub-fraction OB- 6. Triple channel immunofluorescence microscopy was employed to observe the effects of methanolic extract, PEI fraction, sub-fractions OB-5 and OB-6, 3-epi-ursolic acid and oleanolic acid on the cytoskeleton and nuclei of MCF-7 cells. Result: The methanolic extract and the PEI fraction exhibited selectively greater growth inhibition against MCF-7 cell line (TGI: 56 and 36.2 µg/ml, respectively). By using triple channel immunofluorescence microscopy, it was observed that the methanolic extract, PEI fraction, sub-fraction OB-5 and 3-epi-ursolic acid induced irregular mitotic spindle formation and slowing of mitotic progression in MCF-7 cells while sub-fraction OB-6 induced mitotic arrest in the prophase stage. F-actin aggregation was also visible in PEI fraction, subfraction OB-5 and 3-epi-ursolic acid treated MCF-7 cells. Conclusion: These results emphasize the importance of O. basilicum as a potential novel non-toxic alternative to the conventional anticancer therapy and suggest that it inhibits the growth of MCF-7 cancer cells via multiple mechanisms such as interaction with the microtubules and mitotic spindle apparatus, and F-actin aggregation.

A phenanthrene[9,10-d]imidazole-phenol-based fluorescent probe combined ESIPT and AIE for “turn-on” detection of Cu2+ with a green-emitting and improved stokes shift and its application

2021 ◽  
Author(s):  
Jiahui Du ◽  
Bing Zhao ◽  
Wei Kan ◽  
Haochun Yin ◽  
Tianshu Song ◽  
...  
Keyword(s):  
Fluorescent Probe ◽  
Stokes Shift ◽  
Fluorescent Sensors ◽  
Turn On ◽  
Highly Sensitive

Development of highly sensitive and selective fluorescent sensors toward Cu2+ has gained considerable attention in view of its application of environmental and biological fields. However, the strategy of sensing by...

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