Virtual Tour of the Microscope

Running Head: VIRTUAL TOUR OF THE MICROSCOPE

Week 4

Virtual Tour of the Microscope

Asdrubal Atehortua

Professor: Asma Sayed

BIOS-135

Foundation of Biology & Chemistry with Lab

VIRTUAL TOUR OF THE MICROSCOPE 2

Week IV

Virtual Tour of the Microscope

Introduction:

The Microscopes are very necessary tools in biology. We use

microscopes to see the smallest parts so we can see this world

applied to view the tiny, in this ilab we used a compound light

microscope, and Light microscopes magnify the image of the

specimen using light and lenses. The term compound means that

this microscope passes light through the specimen and then

through two different lenses. The lens closest to the specimen is

called the objective lens, while the lens nearest to the user’s

eye is called the ocular lens or eyepiece. When you use a

compound light microscope, the specimen being studied is placed

on a glass slide, the slide may be either a prepared slide that

is permanent and was purchased from a science supply company.


Types of structural information that each type of microscope can

provide:

“Optical Microscopes: These microscopes use visible light to make

an image. The light is refracted with optical lenses. Optical

microscopes can be further subdivided into several categories:

Compound Microscope: These microscopes are composed of two lens

systems, an objective and an ocular (eye piece).

Confocal Laser scanning microscope: Unlike compound and stereo

microscopes, these devices are reserved for research

organizations. They are able to scan a sample also in depth. A

computer is then able to assemble the data to make a 3D image.

X-ray Microscope: these microscopes use a beam of x-rays to

create an image.

Scanning acoustic microscope (SAM): These devices use focused

sound waves to generate an image. SAMs can also be used in

biology where they help to uncover tensions, stress and

elasticity inside biological structure.


Scanning Helium Ion Microscope (SHIM or HeIM): these devices use

a beam of Helium ions to generate an image.

Neutron Microscope: These microscopes are still in an

experimental stage. They have a high resolution and may offer

better contrast than other forms of microscopy.

Electron Microscopes: Modern electron microscopes can magnify up

to 2 million times. Transmission electron microscopy (TEM): In

this case, the electron beam is passed through the sample. The

result is a two dimensional image.

Scanning electron microscopy (SEM): Here the electron beam is

projected on the sample. The electrons do not go through the

sample but bounce off. This way it is possible to visualize the

surface structure of the specimen. The image appears 3

dimensional.

Scanning Probe Microscopes: It is possible to visualize

individual atoms with these microscopes. The image of the atom is

computer-generated, however. (Kim, 2014).’’


Various cellular structures and their appearance under

magnification:

Cells are the fundamental physiological and structural units of

most living organisms, Cells are classified into three domains,

Bacteria, Archaea and Eukarya, depending upon their fundamental

structural and biochemical differences. All members of domain

Bacteria consist of prokaryotic cells, which lack membrane-bound

organelles and a defined nucleus. All members of domain Eukarya

consists of eukaryotic cells, which possess membrane organelles

and nuclei. Domain Archaea shares features of both domains

bacteria and Eukarya. Archaea shares the following features with

Bacteria: absence of nuclei, absence of membrane-bound

organelles, and the presence of a circular chromosome. Features

of Eukarya shared with Archaea include the absence of

peptidoglycan in cell walls (not all eukaryotes have cell walls,

however), presence of more than one RNA polymerase, methionine as

the first amino acid of all proteins, presence of some introns in

their genes, immunity to the antibiotics streptomycin and

chloramphenicol, and presence of histones to fold DNA into

chromosomes.


Bacteria

Archaea


Eukarya


Equipment:

1. Light Microscopes


2. Electron Microscope

Parts of a light microscope.

1. Eyepiece or Ocular

2. Objective Lens

3. Stage

4. Stage Clips

5. Diaphragm

6. Light Source


7. Coarse Focus Knob

8. Fine Focus Knob

Materials:

1. skin cells

How microscopes can be used not only to visualize biological

material but also to gather quantitative data.

“Microscopy and MRI are increasingly part of a broader analytical

context that may include quantitative measurement, statistical

analysis, mathematical modeling and simulation and/or automated

reasoning over multiple datasets reflecting different properties

and possibly resulting from different acquisition techniques at

different scales of resolution, often generated at different

institutions, Advances in imaging techniques and high-throughput

technologies are providing scientists with unprecedented

possibilities to visualize internal structures of cells, organs

and organisms and to collect systematic image data characterizing

genes and proteins on a large scale. To make the best use of


these increasingly complex and large image data resources, the

scientific community must be provided with methods to query,

analyze and crosslink these resources to give an intuitive visual

representation of the data.” (Medicine, 2014)

Analog Light Microscope Vs Electron Microscope.

The Advantages and Disadvantages

We have plenty of difference between both microscopes: the

advantages are both are tolls to check small structures and both

help to different areas in biology and other types of sciences.

How we used both microscopes is different, in one we use

electrons and not photons for visualization, we need to be real

that the best advantage in the electron microscope is the higher

resolution and the higher magnification, but the light

magnification is useful but only to +-1000/2000 times up .also

the electron microscope work in places where structures can be

seen by optical microscopy. In the electron microscope we can see


also a 3d image like in the Scanning electron microscopy a agree

that the electron microscopy is extremely expensive, the sample

have to be dry, that’s why we can see living specimens, and

moving specimens everything have to be dead, the image is always

back and white because electrons don have colors even if we used

a live structure the electron have a beam very high and the

sample expose to thios radiation not be able to live.

Conclusion:

Microscopes can be classified based on the physical principle

that is used to generate an image and help to get plenty of new

data, Different microscopes visualize different physical


characteristics of the sample like elasticity can be visualized

with acoustic microscopes. Image contrast, resolution which

determines magnification and destructiveness of the sample are

other relevant parameters to get and view new data, the electron

give plenty of resources but the Light Microscope work perfect to

simple labs.


Test Your Knowledge


Reference

A. Cherif, B. A. (2008). Foundations of Modern Biology and Chemistry: An

Integrated Approach. Pearson Custom Publishing.

Kim, O. (2014). Different types of microscopes. Retrieved from

microbehunter: http://www.microbehunter.com/different-types-

of-microscopes/

Medicine, U. N. (2014). Visualization of image data from cells to organisms.

Retrieved from ncbi:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3650473/


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Virtual Tour of the Microscope