scholarly journals Real-time observation of light-controlled transcription in living cells

2017 ◽  
Author(s):  
Anne Rademacher ◽  
Fabian Erdel ◽  
Jorge Trojanowski ◽  
Karsten Rippe
Keyword(s):  
Real Time ◽  
Gene Cluster ◽  
Living Cells ◽  
Effector Proteins ◽  
High Temporal Resolution ◽  
Activation Process ◽  
Osteosarcoma Cell ◽  
Dynamic Regulation ◽  
Time Observation ◽  
Time Readout

AbstractGene expression is a tightly controlled process that is coordinated in space and time. To dissect its dynamic regulation with high temporal resolution, we introduce an optogenetic tool termed BLInCR (Blue Light-Induced Chromatin Recruitment) that combines rapid and reversible light-dependent recruitment of effector proteins with a real-time readout for transcription. We used BLInCR to control the activity of a reporter gene cluster in the human osteosarcoma cell line U2OS by reversibly recruiting the viral transactivator VP16. RNA production was detectable ∼2 minutes after VP16 recruitment and readily decreased when VP16 dissociated from the cluster in the absence of light. Quantitative assessment of the activation process revealed biphasic activation kinetics with a pronounced early phase in cells treated with the histone deacetylase inhibitor SAHA. Comparison with kinetic models for transcription activation suggests that the gene cluster undergoes a maturation process when activated. BLInCR will facilitate the study of transcription dynamics in living cells.

scholarly journals Real-time observations of stable isotope dynamics during rainfall and throughfall events

2018 ◽  
Author(s):  
Barbara Herbstritt ◽  
Benjamin Gralher ◽  
Markus Weiler
Keyword(s):  
Isotopic Composition ◽  
Real Time ◽  
Temporal Resolution ◽  
Tree Canopy ◽  
Dead Volume ◽  
High Temporal Resolution ◽  
Time Lags ◽  
Mixing Processes ◽  
Hydrologic System ◽  
Time Observation

Abstract. The isotopic composition of throughfall is affected by complex exchange, enrichment, and mixing processes in the tree canopy. All interception processes occur simultaneously in space and time generating a complex pattern of throughfall in amount and isotopic composition. This pattern ultimately cascades through the entire hydrologic system and is therefore crucial for studies in catchment hydrology where recharge areas are often forested while reference meteorological stations are generally in the open. For the quasi real-time observation of the isotopic composition of both gross precipitation and throughfall we developed an approach combining an off-the-shelf membrane contactor (Membrana) with a laser-based Cavity Ring-Down Spectrometer (CRDS, Picarro), obtaining isotope readings every two seconds. For the continuous observation of the temporal effect of interception processes two setups with two CRDS instruments in parallel were used analysing gross precipitation and throughfall simultaneously. All devices were kept small to minimize dead volume and thereby, with time-lags of only four minutes, to increase the temporal resolution of isotope observations. Complementarily, meteorological variables were recorded in high temporal resolution at the same location. Comparing these high temporally resolved continuous measurements with discrete liquid or event-based bulk samples, this approach proves to be a powerful tool towards more insight in the very dynamic processes contributing to interception during rainfall events.

scholarly journals Real-time observation of light-controlled transcription in living cells

2017 ◽  
Vol 130 (24) ◽  
pp. 4213-4224 ◽  
Author(s):  
Anne Rademacher ◽  
Fabian Erdel ◽  
Jorge Trojanowski ◽  
Sabrina Schumacher ◽  
Karsten Rippe
Keyword(s):  
Real Time ◽  
Living Cells ◽  
Time Observation ◽  
Real Time Observation

Real-time subcellular imaging based on graphene biosensors

Nanoscale ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 1759-1765 ◽  
Author(s):  
Lixun Sun ◽  
Yuquan Zhang ◽  
Yijia Wang ◽  
Yong Yang ◽  
Chonglei Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
Optical Sensors ◽  
Living Cells ◽  
The Real ◽  
Time Observation ◽  
Real Time Observation ◽  
Subcellular Imaging

Graphene optical sensors enable the real-time observation of subcellular dynamics in living cells.

Third-generation GFP biosensors for real-time readout of pH and redox potential in living cells

2004 ◽  
Author(s):  
Stephen J. Remington ◽  
George T. Hanson ◽  
Mark Canon ◽  
Robert Aggeler ◽  
Devin Oglesbe ◽  
...  
Keyword(s):  
Redox Potential ◽  
Real Time ◽  
Living Cells ◽  
Third Generation ◽  
Time Readout

Real-time observation of vortex lattices in a superconductor

1993 ◽  
Vol 51 ◽  
pp. 1050-1051
Author(s):  
K. Harada ◽  
T. Matsuda ◽  
J.E. Bonevich ◽  
M. Igarashi ◽  
S. Kondo ◽  
...  
Keyword(s):  
Real Time ◽  
Flux Line ◽  
Electron Holography ◽  
Lorentz Microscopy ◽  
Vortex Lattices ◽  
Flux Lines ◽  
Magnetic Flux Lines ◽  
Time Observation ◽  
Thin Superconductor ◽  
Real Time Observation

Previous observations of magnetic flux-lines (vortex lattices) in superconductors, such as the field distribution of a flux-line, and flux-line dynamics activated by heat and current, have employed the high spatial resolution and magnetic sensitivity of electron holography. And recently, the 2-D static distribution of vortices was also observed by this technique. However, real-time observations of the vortex lattice, in spite of scientific and technological interest, have not been possible due to experimental difficulties. Here, we report the real-time observation of vortex lattices in a thin superconductor, by means of Lorentz microscopy using a 300 kV field emission electron microscope. This technique allows us to observe the dynamic motion of individual vortices and record the events on a VTR system.The experimental arrangement is shown in Fig. 1. A Nb thin film for transmission observation was prepared by chemical etching. The grain size of the film was increased by annealing, and single crystals were observed with a thickness of 50∼90 nm.

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