Fichas
Microscopy
Fichas del conjunto (18)
- 1Small IntestineThe small intestine is part of the digestive system. At first glance it looks like a tube of a couple of centimeters in diameter that is connected to the stomach. It is surrounded by two layers of smooth muscles that contract in a wavelike pattern.
- 2Cells types of the EpiteliumThe epithelium consists of different cell types. The most abundant cells are enterocytes, which are also called intestinal absorptive cells, because their apical membrane and glycocalix is packed with digestive enzymes and transporters.
- 3Inflammation of the small intestineThe epithelium of the small intestine is constantly exposed to a range of microorganisms and foreign substances. It provides both a physical and immunological barrier against these exterior challenges.
- 4Light microscopyLight microscopy is limited to a minimal resolution of approximately 200 nanometers (nm). The minimal resolution is defined as the distance between two points that are still distinguishable as two separate entities.
- 5Staining techniquesMost cells are almost transparent and it is very hard to distinguish any structures. To better visualize cells and their specific components you can use chemicals that stain certain structures.
- 6Transmission Electron MicrooscopyTransmission Electron Microscopes (TEM) work similar to light microscopes, but they utilize electrons instead of light. Electrons have wavelike properties. Due to their high energy, electrons have a very short wavelength.
- 7Fluorescence MicroscopyFluorescence microscopes take advantage of the difference in emission and transmission wavelengths of fluorophores to produce high contrast images.
- 8Fluorence microscopesA fluorescence microscope is similar to a light microscope. Instead of shining the whole spectrum of visible light through the specimen, the fluorescent microscope only shines a specific wavelength on the sample.
- 9Light microscopeA light microscope illuminates the specimen by focusing light through a lens onto the microscope slide. The light passes through the specimen and into the objective lenses.
- 10SpecimenDry mount: The specimen is placed directly on the slide.
Wet mount: A drop of water is used to suspend the specimen between the slide and cover slip.
Section mount: An extremely thin cross-section of a specimen is used.
Smear: A thin layer of the specimen is smeared carefully across a slide before applying a cover slip. - 11FluorophoreWhen light is absorbed by a substance it results in the excitement of an electron into a higher state. When the electron jumps back into the lower electronic state it emits the energy as electromagnetic waves.
- 12Fluorescent dyesFluorescent dyes are fluorophores that bind to specific cellular structures.
- 13DAPIDAPI is a fluorescent dye that strongly binds to A-T-rich regions of DNA.
- 14CY3 and CY5Cy3 and Cy5 fluorescent dyes bind to DNA.
- 15MicroscopyScientists use microscopes (micro- = “small”; -scope = “to look at”) to study structures that are too small to see with the naked eye, like most cells. A microscope is an instrument that magnifies an object.
- 16Electron MicrosopyElectrons have wavelike properties. Due to their high energy, electrons have a very short wavelength. This translates into much higher resolutions than what would be possible with light microscopes.
- 17Transmission Electron Microscopesuse a high voltage electron beam to produce an image, and the electrons that pass through the sample are detected.
- 18Light Microscopy sample preparationOften additional steps are required to achieve satisfying results. Most of these methods kill the cells, hence light microscopy is not ideal to visualize processes in living cells. Protocols vary depending on the sample and microscope. Below is the general process for histology preparations.
Preparation:
Fixation - chemical fixatives preserve tissue by preventing degradation, and help to maintain the structure of the cell and of sub-cellular components. The most common fixative for light microscopy is 10% neutral buffered formalin.
Dehydration - water is removed from the sample as it does not mix with embedding media.
Embedding - the sample is embedded in a solid external matrix to facilitate sectioning.
Sectioning - the specimen is cut into thin sections. The thickness of the sections depends on the sample and research question. For routine histology, these slices are 2-5 micrometers thick.
Mounting - attaching samples to the microscopy slide.
Staining - sample is stained to add contrast and label structures of interest.
Información
- Descripción
- Fichas sobre Microscopy, creado por DIEGO ARTURO ALVAREZ CONTRERAS el 29/09/2023.
- Creado por
- DIEGO ARTURO ALVAREZ CONTRERAS
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