Using a microscope
When using a microscope, a few small errors might occur:
- If the magnification has been set too high.
For observing sections of simple objects, a magnification of between 50x and 300x is sufficient. Only when very thin objects with a microtome or samples are being observed is it suitable to increase the magnification. Likewise, we use magnifications of 1000x or higher for the analysis of blood.
- The preperation deteriorates with a false adjustment of the lens.
With higher magnifications, it is possible to first adjust the focus before the lense affects the sample. As such, for a suitable adjustment, the lens will be closed against the stage. After, the clarity of the eyepiece can be adjusted with care.

Cleaning microscopes.
A prerequisite for obtaining clear images with the microscope is that the lens is clean. The biggest problem is dust. It can come from the objects being observed or as dust in the environment that the miscroscope is being used. It is very important to protect the lenses from dust to ensure that it does not have the opportunity to damage the lens surface. When the device is not in use, ensure that it is covered to protect it from exposure to dust and make sure that the cover is kept clean to make sure that it is protecting the microscope. It's important to differentiate between the kinds of dirt on the lenses when they are going to be cleaned: dust particles (residue from glass slides or fabrics, etc.) and dirt in general (fingerprints, etc).

1. Ocular
2. Arm
3. Stages
4. Gross and fine setting
5. height stages setting
6. Base
7. Light source
8. Condenser
9. claw
10. Objective lens
11. Revolver
12. Tube

Microscopes are formed by different  parts: an optical and a mechanical part. Here follows a short description of these parts:

 - Ocular: Are the lenses situated the closest to the beholder viewer
 - Arm: Situated perpendicullary to the base, they can be vertical or arched, so that they can joined to the base.
 - Stage: Is the part that holds the sample, it consists on two grippers and the hole from wich comes the light to
   observe the sample
 - Macrometric fitting: An screw for focus and choose lenses on a quick way
 - Micrometric fitting. An screw for focus and choose lenses on a slow way
 - Stage fitting: An screw that fits the stage
 - Base: is the part that holds the microscope
 - Light souce: It is used to light the samples or items to be observed, it is isolated on the base.
 - Grippers: Two grippers located on the stage. Their aim is holding the samples
 - objective lens: The lense situated the closest to the sample
 - Revolver: Is the part that holds the set of objective lenses, it allows to change them.
 - Tube: Is the part were the ocular is, it holds the revolver with the objective lenses on the bottom and the oculars on
   the top.

Different types of microscopes

Simple microscopes: They just use a single  magnifying glass

Composite microscopes: They are formedby a kit of glasses, in a way that they allow to magnify the image trough them. (optics microscopes).

Electronic microscopes: They use electrons instead of visible light (fotons) to provide images of small items. Those icroscopes increase the speed of electrons to get a shorted wavelength and a better resolution (electrons have a wavelength rather small than visible light, so they are able to break up very small structures) It gives a magnification capacity about 500.000 magnifications compared to other optical microscopes. The images obtained are on black and white as they use electrons instead of light. The electronic spotis produced by a Wolframic cathode. 

Microscopes of reflected light: These microscopes are used mainly to observe transparent and liquid preparations. They are specially used in blood analyse, cells, tests in plants. Classical reflected light microscopes have a really short working distance, under 4 mm. This is why these microscopes are suitable for very thin solutions.

On the image above you can observe a cell that has been tinted for better observation trough microscope 

Solutions are situated on the samples holder and covered with the samples cover lid. Reflected light microscopes are usually offered with a full range of magnification glasses (from 40 to more than 1000). For works of 1000 magnifications it is necessary to put a drop on oil immersion to seal the space between the sample holder and the cover lid. Images until 400 magnifications can be seen without any special technic. The magnification on reflected light microscopes can be increased by changing the oculars

Stereo microscopes using reflected or transmitted light: These microscopes are typically used to view large objects. Their range of uses includes analysing insects, plants, coins or for testing materials. The majority of reflected light microscopes have a working distance of 40mm, making these microscopes ideal for working with large objects or for testing different materials. Normally we offer these microscopes as models with two eye pieces.

Fluorescence microscopes: Used to reveal natural fluorescent molecules, or to reveal an added fluorescence, as when detecting antibodies.

On this image you can see a sample that has not been treated, because it is fluorescent by itself.
This circumstance makes tinting unnecessary

In immunity fluorescence a fluorescent dye (almost always FITC) is added to an antibody. these antibodies can be produced on a very specific way to concrete biological structures. The dyes are extremely selective, but not so intensive as in traditional secondary fluorescence.

For applications that require to keep images there are trinocular microscopes. They consist on binocular microscopes with an additional tube that allows to instal an USB camera that recordes images. These images can later be transfered to a PC or a laptop. It also offers the possibility to connect a microocular to the binocular microscopes. this microocular is simply set to the ocular of themicroscope. This gives the opportunity to turn microscopes on video microscopes in an economical way.

Microscopes in PTB