Ultrahigh-resolution imaging of biological systems based on standing-wave total internal reflection microscopy

2001 ◽  
Author(s):  
Peter T. C. So
Keyword(s):  
Standing Wave ◽  
Total Internal Reflection ◽  
Biological Systems ◽  
Internal Reflection ◽  
Ultrahigh Resolution ◽  
Total Internal Reflection Microscopy ◽  
Resolution Imaging

Super-Resolution Imaging in Fluid Mechanics Using New Illumination Approaches

2020 ◽  
Vol 52 (1) ◽  
pp. 369-393
Author(s):  
Minami Yoda
Keyword(s):  
Fluid Mechanics ◽  
Total Internal Reflection ◽  
Imaging Techniques ◽  
Super Resolution ◽  
Internal Reflection ◽  
Interfacial Flows ◽  
Structured Illumination ◽  
Structured Illumination Microscopy ◽  
Entire Volume ◽  
Resolution Imaging

Quantifying submillimeter flows using optical diagnostic techniques is often limited by a lack of spatial resolution and optical access. This review discusses two super-resolution imaging techniques, structured illumination microscopy and total internal reflection fluorescence or microscopy, which can visualize bulk and interfacial flows, respectively, at spatial resolutions below the classic diffraction limits. First, we discuss the theory and applications of structured illumination for optical sectioning, i.e., imaging a thin slice of a flow illuminated over its entire volume. Structured illumination can be used to visualize the interior of multiphase flows such as sprays by greatly reducing secondary scattering. Second, the theory underlying evanescent waves is introduced, followed by a review of how total internal reflection microscopy has been used to visualize interfacial flows over the last 15 years. Both techniques, which are starting to be used in fluid mechanics, could significantly improve quantitative imaging of microscale and macroscale flows.

Measurement of Ca2+ signaling dynamics in exocrine cells with total internal reflection microscopy

2006 ◽  
Vol 291 (1) ◽  
pp. G146-G155 ◽  
Author(s):  
Jong Hak Won ◽  
David I. Yule
Keyword(s):  
Plasma Membrane ◽  
Total Internal Reflection ◽  
Acinar Cells ◽  
Internal Reflection ◽  
Pancreatic Acinar Cells ◽  
Wide Field ◽  
Exocrine Cells ◽  
Parotid Acinar Cells ◽  
Signaling Dynamics ◽  
Total Internal Reflection Microscopy

In nonexcitable cells, such as exocrine cells from the pancreas and salivary glands, agonist-stimulated Ca2+ signals consist of both Ca2+ release and Ca2+ influx. We have investigated the contribution of these processes to membrane-localized Ca2+ signals in pancreatic and parotid acinar cells using total internal reflection fluorescence (TIRF) microscopy (TIRFM). This technique allows imaging with unsurpassed resolution in a limited zone at the interface of the plasma membrane and the coverslip. In TIRFM mode, physiological agonist stimulation resulted in Ca2+ oscillations in both pancreas and parotid with qualitatively similar characteristics to those reported using conventional wide-field microscopy (WFM). Because local Ca2+ release in the TIRF zone would be expected to saturate the Ca2+ indicator (Fluo-4), these data suggest that Ca2+ release is occurring some distance from the area subjected to the measurement. When acini were stimulated with supermaximal concentrations of agonists, an initial peak, largely due to Ca2+ release, followed by a substantial, maintained plateau phase indicative of Ca2+ entry, was observed. The contribution of Ca2+ influx and Ca2+ release in isolation to these near-plasma membrane Ca2+ signals was investigated by using a Ca2+ readmission protocol. In the absence of extracellular Ca2+, the profile and magnitude of the initial Ca2+ release following stimulation with maximal concentrations of agonist or after SERCA pump inhibition were similar to those obtained with WFM in both pancreas and parotid acini. In contrast, when Ca2+ influx was isolated by subsequent Ca2+ readmission, the Ca2+ signals evoked were more robust than those measured with WFM. Furthermore, in parotid acinar cells, Ca2+ readdition often resulted in the apparent saturation of Fluo-4 but not of the low-affinity dye Fluo-4-FF. Interestingly, Ca2+ influx as measured by this protocol in parotid acinar cells was substantially greater than that initiated in pancreatic acinar cells. Indeed, robust Ca2+ influx was observed in parotid acinar cells even at low physiological concentrations of agonist. These data indicate that TIRFM is a useful tool to monitor agonist-stimulated near-membrane Ca2+ signals mediated by Ca2+ influx in exocrine acinar cells. In addition, TIRFM reveals that the extent of Ca2+ influx in parotid acinar cells is greater than pancreatic acinar cells when compared using identical methodologies.

scholarly journals A light scattering model for total internal reflection microscopy of geometrically anisotropic particles

2019 ◽  
Vol 66 (10) ◽  
pp. 1139-1151 ◽  
Author(s):  
Adrian Doicu ◽  
Alina A. Vasilyeva ◽  
Dmitry S. Efremenko ◽  
Christopher L. Wirth ◽  
Thomas Wriedt
Keyword(s):  
Light Scattering ◽  
Total Internal Reflection ◽  
Internal Reflection ◽  
Anisotropic Particles ◽  
Scattering Model ◽  
Total Internal Reflection Microscopy
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