Tishk International UniversityFaculty of Science Medical Analysis Department

Lab Instrumentation & Lab safety

1st Grade- Fall Semester 2020-2021

Microscope Lect. 6

Dr. Kazhan I. MahmoodKazhan.ibrahim@tiu.edu.iq

Learning outcomes

By the end of this session, you will be able to:

• Define microscope

• Explain the functions of microscope

Definition of microscope

• It is an instrument that produces enlarged images of small objects, allowing the observer an exceedingly close view of minute structures at a scale convenient for examination and analysis.

History

• Three Dutch spectacle makers—Hans Jansen, his son Zacharias Jansen, and Hans Lippershey—have received credit for inventing the compound microscope about 1590.

History cont. (1)

• In 1655 – English natural philosopher Robert Hooke used a compound microscope to observe pores in cork.

• In his book he invented the term cell.

History cont. (2)

• The Dutch civil servant Antonie van Leeuwenhoek began his pioneering observations of freshwater microorganisms in the 1670s.

• He made his postage-stamp-sized microscopes by hand, and the best of them could resolve details around 0.7 μm.

Magnification power

• The magnifying power of a microscope is an expression of the number of times the object being examined appears to be enlarged.

• It is usually expressed in the form 10× (for an image magnified 10-fold).

Types of microscope

• The most familiar type of microscope is the optical (or light) microscope, in which glass lenses are used to form the image.

• Optical microscopes can be simple, consisting of a single lense

or• compound, consisting of several optical

components in line.

Differences

• Single-lensed simple microscopes can magnify up to 300×—and are capable of revealing bacteria

• Compound microscopes can magnify up to 2,000×.

• A simple microscope can resolve below 1 micrometer (μm; one millionth of a metre); a compound microscope can resolve down to about 0.2 μm.

Other types of microscopes

• Other types of microscopes use the wave nature of various physical processes.

• The most important is the electron microscope, which uses a beam of electrons in its image formation.

• The transmission electron microscope (TEM) has magnifying powers of more than 1,000,000×.

Microscope parts

• Always carry with 2 hands• Never touch the lenses with your fingers• Only use lens paper for cleaning• Keep objects clear of desk and cords

Microscope care & safety

Learning objectives

Now, you will be able to:

• Define microscope

• Explain the functions of microscope

Thank you