This document provides an overview of microscopy. It begins with an introduction to microscopes and their history. It then defines key microscope terms and describes different types of microscopes, including their components, working principles, applications and advantages/disadvantages. The document discusses brightfield, darkfield, phase contrast, fluorescence and electron microscopes. It also covers micrometry and best practices for microscope care and storage. In summary, the document provides a comprehensive guide to the basic concepts and components of light and electron microscopy.
Slides includes all details about Dark field Microscopy.
useful for MTech, pharmacy student which dealing with microbiology. also for reference to study Dark Field Microscopy. includes principle, instrumentation, working, uses etc.
Slides includes all details about Dark field Microscopy.
useful for MTech, pharmacy student which dealing with microbiology. also for reference to study Dark Field Microscopy. includes principle, instrumentation, working, uses etc.
Dark-field microscopy is used to illuminate unstained samples causing them to appear bright against a dark background. This type of microscope contains a special condenser having a central blacked-out area.
Introduction
History
Compound microscope
Variants of microscopes
Dark field microscope
Phase contrast microscope
Fluorescent microscope
Polarising microscope
Electron microscope
A Microscope is an instrument for viewing objects that are too small to be seen by the naked/ unaided eyes.
In Greek micron= small
skopien=to look at
The science of investigating small object using such an instrument is called microscopy
The term microscopic means minute or very small, not visible with the eye unless aided by a microscope
From ancient times, man wanted to see things for smaller than could be perceived with the naked eye.
This led to the construction in the 16th century, of a magnifier composed of a single convex lens, and this in turn led to the eventual development of the microscope.
The most famous early pioneers in the history of microscope are Digges of England and Hans & Zcharias Janssen of Holland
It was Antony Van Leeuwenhoek who became the man to make and use a real microscope.
Leeuwenhoek microscope was called as single lens microscope because it had convex lens attached to metal holder and was focused using screws
A **bright field microscope** is a type of compound light microscope that illuminates the background against a stained specimen ¹². It is commonly used in practical labs to study organisms' behavior and characteristics such as size, shape, and arrangement ². The microscope uses light rays to produce a dark image against a bright background ¹. It is specially designed with magnifying glasses known as lenses that modify the specimen to produce an image seen through the eyepiece ¹. The bright field microscope is made up of various parts, including the eyepiece, objective lenses, focusing knobs, and stage ¹.
I hope this helps!
Source: Conversation with Bing, 7/11/2023
(1) Brightfield Microscope (Compound Light Microscope)- Definition .... https://microbenotes.com/brightfield-microscope/.
(2) Bright Field Microscopy - Biology Reader. https://biologyreader.com/bright-field-microscopy.html.
(3) Bright-field microscopy - Wikipedia. https://en.wikipedia.org/wiki/Bright-field_microscopy.
(4) Bright Field Microscope: Definition, Parts, Working Principle, Application. https://microbiologynote.com/bright-field-microscope-definition-parts-working-principle-application/.
Dark-field microscopy is used to illuminate unstained samples causing them to appear bright against a dark background. This type of microscope contains a special condenser having a central blacked-out area.
Introduction
History
Compound microscope
Variants of microscopes
Dark field microscope
Phase contrast microscope
Fluorescent microscope
Polarising microscope
Electron microscope
A Microscope is an instrument for viewing objects that are too small to be seen by the naked/ unaided eyes.
In Greek micron= small
skopien=to look at
The science of investigating small object using such an instrument is called microscopy
The term microscopic means minute or very small, not visible with the eye unless aided by a microscope
From ancient times, man wanted to see things for smaller than could be perceived with the naked eye.
This led to the construction in the 16th century, of a magnifier composed of a single convex lens, and this in turn led to the eventual development of the microscope.
The most famous early pioneers in the history of microscope are Digges of England and Hans & Zcharias Janssen of Holland
It was Antony Van Leeuwenhoek who became the man to make and use a real microscope.
Leeuwenhoek microscope was called as single lens microscope because it had convex lens attached to metal holder and was focused using screws
A **bright field microscope** is a type of compound light microscope that illuminates the background against a stained specimen ¹². It is commonly used in practical labs to study organisms' behavior and characteristics such as size, shape, and arrangement ². The microscope uses light rays to produce a dark image against a bright background ¹. It is specially designed with magnifying glasses known as lenses that modify the specimen to produce an image seen through the eyepiece ¹. The bright field microscope is made up of various parts, including the eyepiece, objective lenses, focusing knobs, and stage ¹.
I hope this helps!
Source: Conversation with Bing, 7/11/2023
(1) Brightfield Microscope (Compound Light Microscope)- Definition .... https://microbenotes.com/brightfield-microscope/.
(2) Bright Field Microscopy - Biology Reader. https://biologyreader.com/bright-field-microscopy.html.
(3) Bright-field microscopy - Wikipedia. https://en.wikipedia.org/wiki/Bright-field_microscopy.
(4) Bright Field Microscope: Definition, Parts, Working Principle, Application. https://microbiologynote.com/bright-field-microscope-definition-parts-working-principle-application/.
during this ppt of microscopes we will be able to know
INTRODUCTION
DEFINITION
HISTORICAL BACKGROUND
VARIABLES USED IN MICROSCOPY
VARIOUS TYPES OF MICROSCOPES
COMPOUND MICROSCOPE - Structure and Function
USE OF MICROSCOPE
CARE OF MICROSCOPE
defintion
A microscope (Greek: micron = small and scopos = aim)
MICROSCOPE - An instrument for viewing objects that are too small to be seen by the naked or unaided eye
MICROSCOPY - The science of investigating small objects using such an instrument is called microscopy
The microscope has evolved a lot from the time of Leeuwenhoek. This presentation gives a brief overview about the types of microscope their principle of function and application.
Microscope and Microscopy
Principal , Function & Difference of various types of Light & Electron microscope.Microscopy is the technical field of using microscopes to view samples & objects that cannot be seen with the unaided eye (objects that are not within the resolution range of the normal eye).
Microscopists explore the relationships between structures & properties for a very wide variety of materials ranging from soft to very hard, from inanimate materials to living organisms, in order to better understand it. Zachariaz Janssen 1585 Robert Hooks 1665
Joseph Jackson Lister1830
Microscopy - Magnification, Resolving power, Principles, Types and ApplicationsNethravathi Siri
Magnification, Resolving power, Principles and Applications of Simple, Compound, Stereozoom, Phase contrast, Fluorescent and Electron microscopes (TEM & SEM).
Microscopy is the technical field that uses microscopes to observe samples which are not in the resolution range of the normal-unaided eye.
Research is "creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization and analysis of evidence to increase understanding of a topic, characterized by a particular attentiveness to controlling sources of bias and error.
This presentation is about the introduction of microscopy, its history, parts of a microscope and different types of microscopes along with a brief discussion of their working principles.
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
3. INTRODUCTION
A Microscope (from the Ancient Greek:, mikrós, "small"
and, skopeîn, "to look" or "see") is an instrument used
to see objects that are too small to be seen by the
naked eye.
Giovanni Faber coined the name microscope for the
compound microscope by Galileo .
Since then microscope continued to play a important role
in every Branch of science.
The only scientific equipment ,Charls Darwin took with
him on the Voyage Of Beagle, was a simple microscope.
4. TIMELINE OF MICROSCOPE
• 1590 :- Two Dutch eye
glass makers,
Zaccharias Janssen and
Hans Janssen
constructed the first
compound light
microscope.
• 1609 - Galileo Galilei
developed a compound
microscope with convex
and a concave lens.
6. Timeline contd….
• 1931 :- Ernst Ruska and Max Knoll developed the
Electron Microscope for which
they won the Nobel Prize in
Physics in 1986.
• 1981 :- Gerd Binnig and Heinrich Rohrer
invented the
Scanning Tunnelling Microscope
Electron microscope
constructed by Ernst
Ruska in 1931
7. TERMS AND DEFINITIONS
RESOLUTION
• It is Also called Resolving Power.
• It refers to the ability to produce separate image of closely placed
objects,sothat they can be distinguished as two separate entities.
• It is calculated by Abbés equation.
NUMERICAL APERTURE
• It is the light gathering capacity of a lens.
NA = n X Sin θ
n – Refractive index of the medium between
the object & the objective lens
Θ – ½ of angular aperture of objective lens
8. Terms & Definition contd….
REFRACTIVE INDEX( RI)
RI = Sin i/Sin r
i = angle of incidence
r = angle of refraction.
Higher the density of the medium, greater the RI.
IMMERSION FLUID
• This is any liquid that occupies the space between the object and
objective lens.
• It can also be used between the condenser and the microscope slide.
• Use of immersion fluid produce a homogeneous optical pathway
which minimize the refraction & maximize the NA and improve the
resolution.
10. PROPERTIES OF MICROSCOPE
• A good microscope should have at least three properties:
Good Resolution
• The resolution power of Human eye - 0.2 mm
Light microscope - 0.2µm.
Electron microscope - 0.5nm.
Good Contrast
• This can be improved by staining the specimen.
Good Magnification
• It can achieve by lens
Ocular Lens, Objective Lens
• The total magnification of microscope =
Power of the objective lens X Power of ocular lens
11. TYPES OF MICROSCOPE
LIGHT MICROSCOPE
Uses sun light or artificial light as source of illumination.
1. Bright Field Microscope
2. Dark Field Microscope
3. Phase Contrast Microscope
4. Fluorescence Microscope
ELECTRON MICROSCOPE
• Uses accelerated electron as source of illumination.
1. Transmission Electron microscope
2. Scanning Electron Microscope
12. The bright field or light microscope forms a dark image against a bright
background ,hence the name is called so.
COMPONENTS
The bright field microscope is divided into 3 parts:
Mechanical Parts
Base , C-Shaped Arm, Mechanical Stage
Magnifying Part
Ocular Lens/Eyepiece, Objective lens
Illumination Part
Condenser, Iris Diaphragm, Light Source, Fine and Coarse adjustment
Knob.
BRIGHT-FIELD MICROSCOPE
14. Bright-field microscope contd…
WORKING PRINCIPLE
The image from in the microscope in two stage.
• First image (i1) formed by the objective lens(L1),Which is magnified,
inverted & real.
• The second image (i2) is formed by ocular lens (L2) which is more
magnified and virtual.
16. Bright-field microscope contd…
PROPERTY LOW POWER HIGH POWER OIL IMMERSION
Magnification
of objective
10x 40x 100x
Magnification of
eyepiece
10x 10x 10x
Total magnification 100x 400x 1000x
Iris diaphragm Partially closed Partially opened Fully opened
Position of condenser Lowest Slightly raised Fully raised
18. Bright-field microscope contd…
APPLICATION
• Used to visualize and study the morphologies, Identification of bacteria,
parasites etc.
ADVANTAGE
• It is simple to use with few adjustments involved while viewing the
image.
• The optics of the microscope do not alter the color of the specimen.
• The microscope can be modified to other type microscope
DISADVANTAGE
• The heat produce by the light source may damage the specimen.
• Biological specimens are often of low contrast and needs to be stained.
• Staining may destroy or introduce artifacts.
• Resolution is limited to 0.2µm .
19. • This is similar to the ordinary light
microscope; however, the condenser
system is modified.
• In dark-field microscope, the
specimen appear bright against a dark
back ground.
• The diaphragm blocks all light from
entering the objective lens except
peripheral light that is reflected from the
specimen .
• The resulting image is a brightly
illuminated specimen surrounded by a
dark (black) field.
DARK-FIELD MICROSCOPE
21. Dark-field microscope contd…
APPLICATION
• It identifies the living,unstained
cells.
• It is also useful for the
demonstration of the motility of
flagellated bacteria and protozoa.
• This can rapidly demonstrate
Treponema pallidum in clinical
specimens.
• It is more useful in examining
external details, such as outlines,
edges, grain boundaries and surface
defects than internal structures.
Darkfield image of Treponema pallidum,
22. PHASE CONTRAST MICROSCOPE
• Phase-contrast microscope was first described by Dutch
physicist Frits Zernike.
• When light passes through cells, small phase shifts occur,
which are invisible to the human eye. In a phase-contrast
microscope, these phase shifts are converted into changes in
wavelength, which can be observed as differences in image
contrast.
• COMPONENTS
• Annular condenser
• Phase Plate
25. Phase contrast microscope contd…
APPLICATION
• To see the microbial motility.
• Determine the shape of living cell.
ADVANTAGE
• Living cells can be observed in their natural state.
• No special preparation for fixation or staining etc. is needed to
study.
DISADVANTAGE
• Phase-contrast condensers and objective lenses add considerable
cost to a microscope.
• To use phase-contrast the light path must be aligned.
26. FLUORESCENCE MICROSCOPE
• Refers to any microscope, that uses fluorescence in addition to
reflection and absorption, to generate an image.
• It utilizes a powerful mercury vapor arc lamp for its light source.
• COMPONENTS
• Light Source
• Excitation Filter
• Dichroic mirror
• Emission/Barrier Filter
27. Fluorescence microscope contd…
WORKING PRINCIPLE
• Most cellular components are colourless and cannot be clearly
distinguished under a microscope. The basic principle of fluorescence
microscopy is to stain the components with dyes. Such dye are called
FLUOROCHROMES or FLUOROPHORES
• Fluorochromes, are molecules that absorb excitation light at a given
wavelength (generally UV), and after a short delay emit light at a longer
wavelength.
• The emission light can then be filtered from the excitation light to reveal
the location of the fluorophores.
• The image produced is based on the emission wavelength of the
fluorescent species .
• This result image consist of brightly shine area against the dark
background.
30. APPLICATION
• It is used to study some microbes which directly fluoresce under UV
lamps.
• Some microbes visible under the microscope by staining them with
fluorochromes.
• It is used to detect parasites by QBC method and Tubercle bacilli
ADVANTAGE
• Slides can be examined at a lower magnification, thus allowing the
examination of a much larger area per unit of time
DISADVANTAGE
• Fluorophores lose their ability to fluoresce as they are illuminated in a
process called photobleaching
• The mercury vapour lamp tends to loose their potency with time.
Fluorescence microscope contd…
31. ELECTRON MICROSCOPE
• The Electron microscope was invented by Max Knoll and Earnst Ruska
in1931.
• The electronI microscope uses accelerated electrons as light source
• As wavelength of electron 100,000 times shorter than the visible light,
so resolving power is much better than a light microscope
• The magnified image is visible on a fluorescent screen and can be
recorded on a photographic film.
• Images produced by EM lack color, always shades of black,
gray, and white.
• Electron microscopes are of two types:
1.TEM (Transmission electron microscope)
2.SEM (Scanning electron microscope)
32. EM Contd….
Transmission Electron Microscope (TEM)
• TEM are the method of choice for viewing the detailed structure of cells and
viruses.
• This microscope produces its image by transmitting electrons through
the specimen.
• Because electrons cannot readily penetrate thick specimen, the specimen
must be sectioned into extremely thin slices (20–100 nm) .
Specimen Preparation
To make a suitable specimen following steps are followed
1. Fixation
2. Dehydration
3. Embedding
4. Slicing
33. EM Contd….
Electron Pathway
• Electron generated by electron gun travels in vacuum path, with high
speed, passes through condenser lens bombard to specimen mount on
slide.
• Scatters Objective Ocular Enlarge
electrons lens lens Image
• The thick area of specimen scatters more electron & appears dark and
thin area scatter less & appear bright.
APPLICATION
The important use of EM is for virus detection. It can detect virus
i) Direct from clinical specimen
ii)Tissue culture
iii)After adding specific antiviral antibody to the specimen.
36. EM Contd….
Scanning Electron Microscope (SEM)
• SEM has been used for examining the surface of microorganism in
greater details.
Staphylococcus aureus
37. LIGHT VS ELECTRON MICROSCOPE
FEATURES LIGHT MICROSCOPE ELECTRON
MICROSCOPE
Magnification 1000x – 1500x Over 100,000x
Resolution 0.2µm 0.5nm
Illumination source Visible light Electron beams
Medium of travel Air Vacuum
Specimen mount Glass slide Metal grid
Type of lens Glass Electromagnetic
38. MICROMETRY
• Micrometry refer to the measurement of dimensions of the desire
microorganisms under microscope.
• The most common procedure used in clinical laboratory is by using
a graduated scale (Reticles) located in one eyepiece.
• Reticles must be calibrated against a stage micrometre.
40. CARE OF MICROSCOPE
TRANSPORT
•When carrying your microscope from one part
of the room to another, use both hands to hold the
instrument,
And, under no circumstances should one attempt
to carry two microscopes at one time.
WORKING PLACE
•Should be placed in flat fixed area.
•Away from source of water.
•Workstation should be uncluttered while
doing microscopy.
LENS CARE
•At the beginning of each use, make sure lenses
are clean.
•At the end of each lab session, wipe any
immersion oil from the immersion lens.
The microscope should be held firmly with
both hands while being carried.
When oculars are removed for cleaning,
cover the ocular opening with lens tissue. A blast from
an air syringe or gas canister removes dust and lint.
41. Care of microscope contd…
PUTTING IT AWAY
1. Remove the slide from the stage.
2. If immersion oil has been used, wipe it off the lens and stage .
3. Do not wipe oil off slides you wish to keep. Simply put them into a slide
box and let the oil drain off.
4. Rotate the low-power objective into position.
5. If the microscope has been inclined, return it to an erect position.
6. If the microscope has a built-in movable lamp, raise the lamp to its highest
position.
7. Set the light intensity adjustment of the microscope to the lowest while
switching it off.
8. If the microscope has a long attached electric cord, wrap it around the
base.
9. Adjust the mechanical stage so that it does not project too far on either
side.
10.Place the dust cover over the microscope at the end of use.