Explanation: Using the low power objective LPO gives us an overview of a specimen. Related questions What is the microscopic nature of cells? What are some examples of the microscopic nature of cells? Why is the microscope important to medical laboratory technology?
What is the purpose of simple staining of cells? Are all bacteria microscopic? Low Power Objective 10X : This next shortest objective is probably the most useful lens for viewing slides. Almost any feature you need to observe in this course can be located with the X total magnification this objective provides.
As an added benefit, the low power objective is always safe to use as it cannot be lowered to the point of contacting and thus possible breaking a slide. This is also true of the scanning objective mentioned above. High Power Objective 40x : This objective sometimes called the "high-dry" objective is useful for observing fine detail such as the striations in skeletal muscle, the arrangement of Haversian systems in compact bone, types of nerve cells in the retina, etc.
Oil Immersion Objective X : This longest objective is used for observing the detail of individual cells such as white blood cells, the cells involved in spermatogenesis, etc.
The lens must be used with a specially formulated oil that creates a bridge between the tip of the objective and the cover slip. Since the refractive indices of air and this lens are different, the lens will not work without this special oil! Microscope objective lenses. The compound microscope is a useful tool for magnifying objects up to as much as times their normal size.
Using the microscope takes lots of practice. Follow the procedures below both to get the best results and to avoid damaging the equipment. The field of view is largest on the lowest power objective. When you switch to a higher power, the field of view closes in towards the center. You will see more of an object on low power. Therefore, it is best to find an object on low power, center it, and then switch to the next higher power and repeat. The depth of focus is greatest on the lowest power objective.
Each time you switch to a higher power, the depth of focus is reduced. Therefore a smaller part of the specimen is in focus at higher power. Again, this makes it easier to find an object on low power, and then switch to higher power after it is in focus.
A common exercise to demonstrate depth of focus involves laying three different colored threads one on top of the other. As the observer focuses down, first the top thread comes into focus, then the middle one, and finally the bottom one. On higer power objectives one may go out of focus as another comes into focus.
When drawing what you see under the microscope, follow the format shown below. It is important to include a figure label and a subject title above the image. The species name and common name if there is one and the magnification at which you were viewing the object should be written below the image.
All relevant parts of the drawing should be labelled on the right side of the image using straight lines. Lines should not cross. Drawings should be done in pencil, while labels should be in pen or typed. Remember that total magnification is determined by multiplying the ocular x objective. You can only view one at a time, so that's all you should be holding. Return it before getting another, and if you break it, tell your instructor so that it can be properly cleaned up and replaced!
Digital microscope for Macintosh or Windows. Investigating pondwater organisms. Powers of 10 version. Make your own microscope. Microscope Notes The compound microscope is a useful tool for magnifying objects up to as much as times their normal size. Parts of the compound microscope.
0コメント