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11 MZB II - Faresse

Introduction to Cell Biology

Introduction to Cell Biology


Set of flashcards Details

Flashcards 38
Language Deutsch
Category Medical
Level University
Created / Updated 31.03.2016 / 05.12.2019
Licencing Not defined
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Auflösungsvermögen von

- menschliches Auge
- Lichtmikroskop
- Elektronenmikroskop

s.B.

Magnification vs. Resolution

• Magnification is the number of times an image's size is enlarged.
• Resolution is a measurement of how well the smallest details of an image can be discerned.

limit of the resolution of a microscope (generally)

- im Lichtmikroskop

- im Elektronenmikroskop

Object that’s less than half the wavelength of the microscope’s illumination source is not visible under that microscope.

Light microscopes use visible light which has a minimum wavelength of 400 nm
-> This means that we will never be able to see any object smaller than approximately 200 nm using a light microscope

The wavelength of electrons is thousand of times shorter than visible light (0.4 nm).
-> This means that we will be able to see objects of approximately 0.2 nm using an EM.

Aufbau Lichtmikroskop

3 elements are required:
- A bright light focused onto the specimen by a condenser.
- A specimen thin enough to allow light to pass through it.
- An appropriate set of lenses to focus the image in our eye.

Tissue preparation

die unterschiedlichen Schritte und wozu diese nötig sind

1. Fixation
- Stop all biochemical reactions
- Preserves tissues from decay
- Generally with Aldehydes PFA or GA
2. Dehydration Embedding
- To prepare embedding
- Baths of alcohol to remove the water
- Bath of Xylol to remove alcohol
3. Embedding
- To harden the tissue
- Immersion in melted, paraffin, resin, or plastic
- Hard after cooling, easier to cut
4. Sectioning
- Using a Microtome
- Light microscope (210 µm)
- Electron microscope (40-100 nm)
5. Staining
- Rehydration using a baths of diluted alcohols
- Immersion in staining solutions

Immunostaining (immunfärbung)

Prinzip

Immunostaining is a general term in biochemistry that applies to any use of an antibody-based method to detect a specific protein in a sample

Fluorochrome

Prinzip

FluorochromeFluoreszenzfarbstoffe, Moleküle, die in der Lage sind, eingestrahlte Energie in Form von Fluoreszenzlicht (Fluoreszenz) wieder abzugeben
-> Licht mit einer bestimmten Wellenlänge wird Absoriert und anschliessend wird licht mit einer anderen bestimmten Wellenlänge abgegeben

Fluorescence microscope

Prinzip

Filter 1: allows only wavelengths that excite the fluorochrome
Filter 2: allows only the light emitted by the fluorochrome