CELL201 Lecture Notes - Lecture 2: Long Term Ecological Research Network, Eosin, Haematoxylin
30 Jun 2018
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CELL BIO- Lecture 2!
Microscopy
Light microscope:!
Condenser lens focuses the light on the specimen!
Compound microscope: !
More than one lens. Much smaller specimens!
Cell theory: !
All living things are made of cells!
Modern microscope: !
-Involves cameras, computers and advanced set ups. !
-High powered light surge !
Microtome: !
-Allows multiple analyses of the same sample to be carried out!
-Allows to see what it looks like inside cells. !
-Make very thin slices ; almost as thin as a cell (two molecules thick?).!
-Allows you to see the internal structures and symmetry of a cell. !
-Allows you to see very fine and thin details within layers of cell.!
-Advantage: 1. The finer the slice the more experiments can be made. Useful in biobanks. More
""experiments can be done from a single specimen.!
" 2. If samples are precious, many experiments can be done from one sample " "
"" without needing many, eventually cutting down expense and also conserving " "
" the samples. !
-Example :!
Visible human project: Microtome sectioning of entire human being done one on one male and
female. Section things and see the internal structures. !
Contrast !
-Needed to distinguish between structures that might be similar in size and shape by taking
advantage of the different chemical properties!
-Any structure with a certain chemical property will be stained with a specific color.!
-Intensity also varies depending on the amount of the specific property present.!
-If not stained, two structure of the same size and shape could be thought of as the same thing
but when stained we can conclude that they are different structures with different properties
(and functions).!
-Hematoxylin and Eosin are two stains!
Hematoxylin
-Blue!
-Positively charged/basic !
-Binds to negative charges, acidic/basophilic structures !
Eosin
-Orange/Pink/Red!
-Negatively charged/acidic !
-Binds positive charges , basic/acidophilic structures!
Tissue microarrays
-Chips/slides with tiny slices of many different samples (e.g tumors)!
Resolution
-Limit of Resolution: How far apart objects must be to appear distinct!
-Determines what can bee seen!
-Smaller the limit of resolution, better the resolving power and smaller the objects that can be
distinguished.!
-Better lenses improve resolution!
-There are other ways that improve resolution!
Document Summary
Condenser lens focuses the light on the specimen. Allows multiple analyses of the same sample to be carried out. Allows to see what it looks like inside cells. Allows you to see the internal structures and symmetry of a cell. Allows you to see very ne and thin details within layers of cell. The ner the slice the more experiments can be made. More experiments can be done from a single specimen. If samples are precious, many experiments can be done from one sample without needing many, eventually cutting down expense and also conserving the samples. Visible human project: microtome sectioning of entire human being done one on one male and female. Needed to distinguish between structures that might be similar in size and shape by taking advantage of the di erent chemical properties. Any structure with a certain chemical property will be stained with a speci c color.
