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Histochemistry and Cell Biology Apr 2019The process of fluorescence starts with the efficient generation of light that is required for the excitation of fluorophores. As such, light sources are a crucial...
The process of fluorescence starts with the efficient generation of light that is required for the excitation of fluorophores. As such, light sources are a crucial component of a fluorescence microscope. Choosing the right illumination tool can not only improve the quality of experimental results, but also the microscope's economic and environmental footprint. While arc lamps have historically proven to be a reliable light source for widefield fluorescence microscopy, solid-state light-emitting diodes (LEDs) have become the light source of choice for new fluorescence microscopy systems. In this paper, we demonstrate that LEDs have superior light stability on all timescales tested and use less electrical power than traditional light sources when used at lower power outputs. They can be readily switched on and off electronically, have a longer lifetime and they do not contain mercury, and thus are better for the environment. We demonstrate that it is important to measure light source power output during warm-up and switching, as a light source's responsiveness (in terms of power) can be quite variable. Several general protocols for testing light source stability are presented. A detailed life cycle analysis shows that an LED light source can have a fourfold lower environmental impact when compared to a metal halide source.
Topics: Lighting; Microscopy, Fluorescence
PubMed: 30767050
DOI: 10.1007/s00418-019-01776-6 -
Indian Journal of Ophthalmology Oct 2019To evaluate light exposure from microscope versus intracameral illuminations to patient's and surgeon's retina during cataract surgery. (Comparative Study)
Comparative Study
PURPOSE
To evaluate light exposure from microscope versus intracameral illuminations to patient's and surgeon's retina during cataract surgery.
METHODS
Thirty consecutive patients who had cataract surgery using microscope and intracameral illuminations. At the point of the ocular of an operating microscope, optical illuminance and irradiance from the microscope illumination (60, 40, 20% intensity) and the intracameral illumination (60% intensity) were measured using a light meter and a spectrometer at a pause after lens capsule polishing in cataract surgery.
RESULTS
Average illuminance (lux) was 1.46, 0.66, 0.27, and 0.1 from 60%, 40%, 20% intensity microscope illuminations and 60% intracameral illumination. Average total spectral irradiance (μW/cm2) was 1.25, 0.65, 0.26, and 0.03 from 60%, 40%, 20% intensity microscope illuminations and 60% intracameral illumination.
CONCLUSION
Microscope ocular illuminance and irradiance during cataract surgery were higher in the microscope illumination than in the intracameral illumination. It suggests that light exposure reaching patient's and surgeon's retina during cataract surgery is lower in the intracameral illumination than in the microscope illumination.
Topics: Aged; Aged, 80 and over; Female; Humans; Lens Implantation, Intraocular; Light; Lighting; Male; Microscopy; Middle Aged; Operative Time; Phacoemulsification; Prospective Studies; Radiation Dosage; Radiation Injuries; Retina
PubMed: 31546495
DOI: 10.4103/ijo.IJO_316_19 -
Sensors (Basel, Switzerland) Oct 2021Lightfield microscopy has raised growing interest in the last few years. Its ability to get three-dimensional information about the sample in a single shot makes it...
Lightfield microscopy has raised growing interest in the last few years. Its ability to get three-dimensional information about the sample in a single shot makes it suitable for many applications in which time resolution is fundamental. In this paper we present a novel device, which is capable of converting any conventional microscope into a lightfield microscope. Based on the Fourier integral microscope concept, we designed the lightfield microscope eyepiece. This is coupled to the eyepiece port, to let the user exploit all the host microscope's components (objective turret, illumination systems, translation stage, etc.) and get a 3D reconstruction of the sample. After the optical design, a proof-of-concept device was built with off-the-shelf optomechanical components. Here, its optical performances are demonstrated, which show good matching with the theoretical ones. Then, the pictures of different samples taken with the lightfield eyepiece are shown, along with the corresponding reconstructions. We demonstrated the functioning of the lightfield eyepiece and lay the foundation for the development of a commercial device that works with any microscope.
Topics: Lighting; Microscopy
PubMed: 34640939
DOI: 10.3390/s21196619 -
Current Protocols in Cytometry May 2001In order to obtain good images using any microscopic imaging modalities, it is necessary to understand the microscope thoroughly and set up properly. This unit should be...
In order to obtain good images using any microscopic imaging modalities, it is necessary to understand the microscope thoroughly and set up properly. This unit should be required reading for all students and staff using a light microscope. It clearly defines the types of illumination used in microscopes and details the correct set up and operation.
Topics: Equipment Design; Light; Microscopy; Optics and Photonics; Photomicrography; Reproducibility of Results
PubMed: 18770701
DOI: 10.1002/0471142956.cy0207s02 -
The Journal of Histochemistry and... Feb 2011Light sheet fluorescence microscopy (LSFM) functions as a non-destructive microtome and microscope that uses a plane of light to optically section and view tissues with... (Review)
Review
Light sheet fluorescence microscopy (LSFM) functions as a non-destructive microtome and microscope that uses a plane of light to optically section and view tissues with subcellular resolution. This method is well suited for imaging deep within transparent tissues or within whole organisms, and because tissues are exposed to only a thin plane of light, specimen photobleaching and phototoxicity are minimized compared to wide-field fluorescence, confocal, or multiphoton microscopy. LSFMs produce well-registered serial sections that are suitable for three-dimensional reconstruction of tissue structures. Because of a lack of a commercial LSFM microscope, numerous versions of light sheet microscopes have been constructed by different investigators. This review describes development of the technology, reviews existing devices, provides details of one LSFM device, and shows examples of images and three-dimensional reconstructions of tissues that were produced by LSFM.
Topics: Animals; Image Processing, Computer-Assisted; Lasers; Light; Microscopy, Fluorescence; Specimen Handling
PubMed: 21339178
DOI: 10.1369/0022155410394857 -
Current Protocols Jul 2022In this paper, we review lightsheet (selective plane illumination) microscopy for mouse developmental biologists. There are different means of forming the illumination... (Review)
Review
In this paper, we review lightsheet (selective plane illumination) microscopy for mouse developmental biologists. There are different means of forming the illumination sheet, and we discuss these. We explain how we introduced the lightsheet microscope economically into our core facility and present our results on fixed and living samples. We also describe methods of clearing fixed samples for three-dimensional imaging and discuss the various means of preparing samples with particular reference to mouse cilia, adipose spheroids, and cochleae. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC.
Topics: Animals; Imaging, Three-Dimensional; Lighting; Mice; Microscopy, Fluorescence
PubMed: 35838628
DOI: 10.1002/cpz1.448 -
Optics Express Jan 2016Brillouin spectroscopy has been used to characterize shear acoustic phonons in materials. However, conventional instruments had slow acquisition times over 10 min per 1...
Brillouin spectroscopy has been used to characterize shear acoustic phonons in materials. However, conventional instruments had slow acquisition times over 10 min per 1 mW of input optical power, and they required two objective lenses to form a 90° scattering geometry necessary for polarization coupling by shear phonons. Here, we demonstrate a confocal Brillouin microscope capable of detecting both shear and longitudinal phonons with improved speeds and with a single objective lens. Brillouin scattering spectra were measured from polycarbonate, fused quartz, and borosilicate in 1-10 s at an optical power level of 10 mW. The elastic constants, phonon mean free path and the ratio of the Pockels coefficients were determined at microscopic resolution.
Topics: Equipment Design; Equipment Failure Analysis; Image Enhancement; Lenses; Lighting; Microscopy, Confocal; Refractometry; Reproducibility of Results; Sensitivity and Specificity
PubMed: 26832263
DOI: 10.1364/OE.24.000319 -
Journal of Biomedical Optics Sep 2018Mobile phone technology has led to implementation of portable and inexpensive microscopes. Light-emitting diode (LED) array microscopes support various multicontrast...
Mobile phone technology has led to implementation of portable and inexpensive microscopes. Light-emitting diode (LED) array microscopes support various multicontrast imaging by flexible illumination patterns of the LED array that can be achieved without changing the optical components of the microscope. Here, we demonstrate a mobile-phone-based LED array microscope to realize multimodal imaging with bright-field, dark-field, differential phase-contrast, and Rheinberg illuminations using as few as 37 LED bulbs. Using this microscope, we obtained high-contrast images of living cells. Furthermore, by changing the color combinations of Rheinberg illumination, we were able to obtain images of living chromatic structures with enhanced or diminished contrast. This technique is expected to be a foundation for high-contrast microscopy used in modern field studies.
Topics: Cell Phone; Image Processing, Computer-Assisted; Lighting; Microscopy, Phase-Contrast
PubMed: 30246509
DOI: 10.1117/1.JBO.24.3.031007 -
Journal of Neurosurgical Anesthesiology Jul 2013Operating microscopes used during neurosurgery are fitted with xenon light. Burn injuries have been reported because of xenon microscope lighting as the intensity of...
BACKGROUND
Operating microscopes used during neurosurgery are fitted with xenon light. Burn injuries have been reported because of xenon microscope lighting as the intensity of xenon light is 300 W. We designed this study to find out if the light of operating microscope causes an increase in temperature of the brain tissue, which is exposed underneath.
METHODS
Twenty-one adult patients scheduled for elective craniotomies were enrolled. Distal esophageal temperature (T Eso), brain temperature under the microscope light (T Brain), and brain temperature under dura mater (T Dura) were measured continuously at 15-minute intervals during microscope use. The irrigation fluid temperature, room temperature, intensity of the microscope light, and the distance of the microscope from the brain surface were kept constant.
RESULTS
The average age of the patients was 44±15 years (18 males and 3 females). The mean duration of microscope use was 140±39 minutes. There were no significant changes in T Brain and T Dura and T Eso over time. T Dura was significantly lower than T Brain both at time 0 and 60 minutes but not at 90 minutes. T Brain was significantly lower than T Eso both at time 0 and 60 minutes but not at 90 minutes. The T Dura remained significantly lower than T Eso at 0, 60, and 90 minutes.
CONCLUSION
Our study shows that there is no significant rise in brain temperature under xenon microscope light up to 120 minutes duration, at intensity of 60% to 70%, from a distance of 20 to 25 cm from the brain surface.
Topics: Adult; Aged; Anesthesia, General; Body Temperature; Brain; Craniotomy; Dura Mater; Female; Humans; Lighting; Male; Microscopy; Middle Aged; Neurosurgical Procedures; Sample Size
PubMed: 23459259
DOI: 10.1097/ANA.0b013e3182894a01 -
Cytometry. Part a : the Journal of the... Mar 2012Proper illumination is essential for light microscopy. Whereas in early years incandescent light was the only illumination, today, more and more specialized light... (Review)
Review
Proper illumination is essential for light microscopy. Whereas in early years incandescent light was the only illumination, today, more and more specialized light sources, such as lasers or arc lamps are used. Because of the high efficiency and brightness that light-emitting diodes (LED) have reached today, they have become a serious alternative for almost all kinds of illumination in light microscopy. LED have a high durability, do not need expensive electronics, and they can be switched in nanoseconds. Besides this, they are available throughout the UV/Vis/NIR-spectrum with a narrow bandwidth. This makes them ideal light sources for fluorescence microscopy. The white LED, with a color temperature ranging from 2,600 up to 5,000 K is an excellent choice for bright-field illumination with the additional advantage of simple brightness adjustments without changing the spectrum. This review discusses the different LED types, their use in the fluorescence microscope, and discusses LED as specialized illumination sources for Förster resonance energy transfer and fluorescent lifetime imaging microscopy.
Topics: Equipment Design; Fluorescence Resonance Energy Transfer; Light; Lighting; Microscopy, Confocal; Microscopy, Fluorescence
PubMed: 22290727
DOI: 10.1002/cyto.a.22023