light microscope vs. electron microscope

LIGHT VS. ELECTRON MICROSCOPE

PRESENTED BY:GROUP 1:

REMIEL ALQUILETAJAMICA AMBION

CELLINE ANCHETAHUB 42

HISTORY• the 1590's, two Dutch spectacle makers, Zacharias

Jansen and his father Hans started experimenting with these lenses

HISTORY

• Anton van Leeuwenhoek  a Dutch draper and scientist, and one of the pioneers of microscopy who in the late 17th century became the first man to make and use a real microscope.

HISTORY

• Hooke's Micrographia,  is Robert Hooke’s most famous work and is notable for the stunning illustrations, drawn by himself.

HISTORY• Modern compound microscopesWith the advancement of technology and improved optics, the microscope as we know it today came into being.

USES OF MICROSCOPE

• Cytology• Pharmacoloy• Microbiology• Histology

RESOLVING POWER

• Ability of a microscope to differentiate between two close together objects.• Higher resolution means

that objects are closer together and can be seen as separate points.

LIGHT MICROSCOPE

• The term light refers to the method by which light transmits the image to your eye. • Microscope is the combination of two words; "micro" meaning

small and "scope" meaning view.• Optical microscopes are the oldest design of microscope• Using a light microscope, one can view cell walls, vacuoles,

cytoplasm, chloroplasts, nucleus and cell membrane. Light microscopes use lenses and light to magnify cell parts. 

TYPES OF LIGHT MICROSCOPE

• A simple microscope is a microscope that uses a lens or set of lenses to enlarge an object through angular magnification alone, giving the viewer an erect enlarged virtual image. • Simple light microscopes of the

past could magnify an object to 266X

TYPES OF LIGHT MICROSCOPE

• Dissecting microscope- magnification: 10-40x- not use for cellular

level- specimens can be

living or non-living.

SAMPLE IMAGE FROM DISSECTING MICROSCOPE

TYPES OF LIGHT MICROSCOPE

• A compound microscope is a microscope which uses a lens close to the object being viewed to collect light (called the objective lens) which focuses a real image of the object inside the microscope• Modern compound light

microscopes, under optimal conditions, can magnify an object from 1000X to 2000X

SAMPLE IMAGES FROM LIGHT MICROSCOPE

ADVANTAGES LIMITATION

• Easy to use• Cheap• True color but

sometimes require staining• Could use live

specimens

• Low resolution due to shorter wavelength of light (0.2nm)• Low magnification (max.

1250x)• Specimen used is thin

ELECTRON MICROSCOPE

• An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination• A transmission electron microscope can achieve better than

50 pm resolution and magnifications of up to about 10,000,000x •  You need to use particles that are smaller than photons to start

with: in other words, you need to use electrons• In an electron microscope, a stream of electrons takes the place of

a beam of light and allows us to see things smaller even than light itself.

SCANNING ELECTRON MICROSCOPE• A Scanning electron

microscopes are designed to make images of the surfaces of tiny objects.

• Advantages:- High resolution (1nm)- Provide detailed images of

surface structures.- High magnification (200,000x)- 3D images

SEM

• Limitations:- expensive- requires extensive

training- sample must be dead

(vacuum, stained)- black and white/false

colour image

TRANSMISSION ELECTRON MICROSCOPE• Transmission electron

microscopes are the most powerful electron microscopes: we can use them to see things just 1 nanometer in size, so they effectively magnify by a million times or more.

• A transmission electron microscope fires a beam of electrons through a specimen to produce a magnified image of an object.

ADVANTAGES DISADVANTAGES

• Higher resolution (1nm)• Provides detailed

images of interior structures• Higher magnification

(500,000x)

• Expensive• Extensive training

required• Samples must be dead

(vacuum, stained)• Black and white/ False

colour images

SUMMARY

REFENCES

• Comparing microscopes: https://www.youtube.com/watch?v=b4WOsYktdn4• Microscopes - SC.912.L.14.4 https://

www.youtube.com/watch?v=6vZZeWqbmU8• http://

www.cas.miamioh.edu/mbiws/microscopes/compoundscope.html#howit works• http://www.history-of-the-microscope.org/history-of-the-mi

croscope-who-invented-the-microscope.php

LABORATORY REAGENT AND PREPARATIONS CALCULATION• Calculate the grams of each substance required to

prepare the following solutions:a. 50 mL of 0.4 M sucroseb. 100 mL of 0.5 M H2SO4

SOLUTIONS!

• A) 50 mL of 0.4 M sucroseM = moles=0.4M = (0.4M)(342) = 136.8 g

• B) 100 mL of 0.5 M H2SO4M = moles=0.5M = (0.5M)(98) = 49 g