Brightfield Illumination Selection
Brightfield Illumination Selection - Related Videos
03:22
Phototaxis Assay of Filamentous Cyanobacteria Using Focused Light Illumination
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2025
Source: Weber, N. et. al., Natural Transformation, Protein Expression, and Cryoconservation of the Filamentous Cyanobacterium Phormidium lacuna. J. Vis. Exp. (2022)This video demonstrates a focused LED-based assay for studying phototaxis in filamentous cyanobacteria. The bacteria migrate toward the light source, forming a dense accumulation at the illuminated center, which is visualized and quantified through pixel intensity analysis of the captured image.
14:29
Capturing Tissue Repair in Zebrafish Larvae with Time-lapse Brightfield Stereomicroscopy
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Cited by 27 •
2015
We present a protocol for capturing the dynamics of zebrafish larval tail fin regeneration on a whole-tissue scale using brightfield-based stereomicroscopy. This technique enables capturing the regeneration dynamics with single cell resolution. This methodology can be adapted to any stereomicroscope equipped with a CCD camera and time-lapse software.
10:07
Highly Resolved Intravital Striped-illumination Microscopy of Germinal Centers
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2014
High-resolution intravital imaging with enhanced contrast up to 120 µm depth in lymph nodes of adult mice is achieved by spatially modulating the excitation pattern of a multi-focal two-photon microscope. In 100 µm depth we measured resolutions of 487 nm (lateral) and 551 nm (axial), thus circumventing scattering and diffraction limits.
07:35
Quantifying Liver Size in Larval Zebrafish Using Brightfield Microscopy
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Cited by 8 •
2020
Here we demonstrate a method for quantifying liver size in larval zebrafish, providing a way to assess the effects of genetic and pharmacologic manipulations on liver growth and development.
06:48
Natural Selection - Concepts
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2019
Fitness Widespread variation of phenotypes in natural populations provides the raw material for evolution, which is the change in the inherited traits of populations over successive generations. Natural selection is one of the main mechanisms of evolution and requires variable traits to be heritable and associated with differential survival and/or reproductive success. Phenotypes that correlate with greater success will have more offspring that survive to reproduce in the next generation, and...
FAQs
Light intensity directly influences image brightness and can also affect how clearly specimen features appear. Too little illumination may make cells, tissues, or microorganisms difficult to distinguish, whereas excessive intensity can increase glare and obscure detail. Selecting a suitable level helps balance visibility with a more informative image for routine observation and later image analysis.
The condenser position and aperture are key adjustments for controlling the transmitted-light conditions reaching the specimen and objective. Their settings can influence contrast, brightness, and the uniformity of the background. Coordinating these controls helps reduce uneven lighting or glare, making structural differences caused by absorption, thickness, or refractive index easier to observe.
Specimen preparation affects how light is modified as it passes through biological material. Differences in thickness, absorption, and refractive index determine which regions appear distinguishable under brightfield conditions. Preparing the sample appropriately and then adjusting illumination to its optical characteristics can improve the visibility of cells, tissues, or microorganisms without relying only on higher light intensity.
Begin by considering the specimen and the image information needed, then adjust transmitted-light intensity, condenser position, and aperture while observing the resulting brightness, contrast, and background uniformity. Specimen preparation should be treated as part of the same process rather than an afterthought. The goal is a clear image with limited glare and useful structural distinction.
This selection process is useful whenever transmitted-light imaging must distinguish biological structures clearly. It supports routine observation and image acquisition in cell biology, histology, and microbiology, where specimens may include cells, tissues, or microorganisms. Appropriate settings also help produce images suitable for quantitative analysis rather than merely visual inspection.
Quantitative analysis depends on images in which brightness, contrast, and background lighting do not obscure relevant specimen features. Adjusting intensity, condenser position, aperture, and preparation conditions helps make structural differences more consistently visible. In cell biology, histology, and microbiology, this supports measurements or comparisons based on images that convey specimen information clearly.