This document provides an introduction to the course "Zoo 457" about biological techniques. It defines biological techniques as methods used to study living things, including experiments, computations, and tools. It then discusses microscopy, noting that a microscope is used to examine small objects and microscopy is the science of investigating small objects using a microscope. It explains the principles of microscopy, including how light is used to create magnified virtual images through objective and oculus lenses. Resolution in microscopy is defined as the minimum distance between two points on a specimen that can be seen as separate entities, which depends on factors like the numerical aperture and wavelength of light used.
2. Course contents
• Definition of biological techniques
• Microscope and microscopy
• Principle of microscopy
• Resulation of microscopy
3. Biological techniques :
Biological techniques are methods or procedures
that are used to study living things. They include
experimental and computational methods,
approaches, protocols and tools for biological
research.
5. A microscope is a laboratory instrument
used to examine objects that are too
small to be seen by the naked eye.
Microscopy is the science of
investigating small objects and
structures using a microscope.
Microscopic means being invisible to
the eye unless aided by a microscope.
8. • microscope enlarges the view of an object by enlarging it twice using the
objective and oculus lenses. It happens in the following way:
• Light from below a specimen illuminates it.
• An objective lens placed very close to the specimen produces a ‘real
image’ of the specimen.
• This image is created somewhere between the two lenses.
• The oculus lens looks at that real image, already magnified, and
creates a ‘virtual image’ of it that is many times magnified.
• This image is created far away, behind the actual objective.
9. • The final image is inverted to the original object, remember that.
• The light passes through the specimen and the two lenses to reach
your eye. In the process, the loss of light can be negligible.
10.
11. Resulation of microscopy,:
In microscopy, the term
“resolution” is used to describe the
ability of a microscope to
distinguish detail of specimen and
Sample.
12. •In other words, the minimum distance between
2 distinct points of a specimen where they can
still be seen by the observer or microscope
camera as separate entities.
13. •The resulation is intrinsically linked to
numerical aperture of optical microscope ‘s
components like objective lens and wavelength
of light Used.
