30504344 Environmental Microscopy Power Point

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Lab 5

Microscopy

Lab Manual pages 71-85



What is Microscopy?

Microscopy: the technical field of usingmicroscopes to view samples or objects.

Very important tool in science

which led to many scientific

discoveries.

Anton van Leeuwenhoek, 16th

century viewer of bacteria

Robert Hooke, first person to

coin the term cell



Types of Microscopes

Optical/LightMicroscopes, which include compound anddissecting/stereo

microscopes

Uses light and lenses tomagnify images

Simple vs. CompoundScopes

Dissecting Compound



Types of Microscopes

Non-optical microscope

Scanning ElectronMicroscope

(SEM)/TransmissionElectron Microscope (TEM)

Produce images byscanning the sample with a

high energy beam of electrons



How TheyWorkOptical

Microscope Non-optical



Optical vs. Non-optical

Characteristics Optical Non-optical

Magnification 40-1200X 25-250,000X

Possible Samples Can be living or deadMu

st be trimmed andcoated/fixed

Resolution Moderate Very High

Benefits Less expensive Very wide depth of

field (3D Images)

Limitations Limited Depth of field Very Expensive andmore difficult to

operate

Depth of field: vertical distance that remains in focus at one time

(decreases as magnification increases in light microscopes)



Parts of the Light Microscope

Ocular

Eyepiece,closest piece to

the eye




Ocular

The lens ormirror of a

microscope

Objective




Ocular

Platform where

slides are

placed (can beadjusted up or

down)

Objective

Stage




Ocular

Holds the slidesin place for

viewing

Objective

Stage

Stage Controls




Ocular

Lens thatfocuses light on

the specimen

Objective

Stage

Stage Controls

Condenser




Ocular

Function is to stopthe flow of light

(can be adjusted

left or righ

t)

Objective

Stage

Stage Controls

Condenser

Diaphragm




Ocular

Controls thestrength of the

light being used

Objective

Stage

Stage Controls

Condenser

Diaphragm

Light Intensity Control




Ocular

Used to focus inon specific

features of the

sample

Objective

Stage

Stage Controls

Condenser

Diaphragm


Coarse

Focus Knob

Fine

Focus Knob




Ocular

Used to powerthe microscope

on and off

Objective

Stage

Stage Controls

Condenser

Diaphragm


Coarse

Focus Knob

Fine

Focus Knob

Power

On/Off



Magnification

Magnify/Magnificaton: to enlarge something in

appearance.

3 Objectives:

1. Scanning (4X)

2. Low (10X)

3. High (40X)The ocular lens (eyepiece) is 10X

Total magnification= objective x ocular



Magnification


appearance.

3 Objectives:

1. Scanning (4X)

2. Low (10X)





Staining

Stains are used in microscopy to increase contrast or color in

specific components of a specimen

Stained Red Blood CellsGram Positive Bacteria:

streptococcus pneumoniae



Clonorchissinensis



Mosquito



Lice



Handling of Microscope

Use lens paper ONLY to clean microscope

lenses

StartA

LL observations on th

e lowestpowered objective (4X)

Only use coarse focus on the low power

(10X) objective and fine focus on high

power (40X) objective



Lab Materials and Trouble Shooting

Microscope Slides Cover Slips



Todays Lab

PART A:

± Table 1, pg.73

± e slide (pgs. 74-75);

± # 12, (Desmids OR Rizophus) ± PreparingWet Mount : 1 drop of Chlorella algae (pg. 76)

± Using a Biological Stain (78): WARNING:Calberla willstain!!!; gloves can be worn if needed; 2 drops of pollen onslide, but only stain 1; during the 5 min it takes to stain you

can start on Part B ± Table 2, pg. 79



Todays Lab

PART B: The Dissecting Microscope

± Figure 1

± e slide

± Pg. 71; Total of 4 specimens: Duckweed, Peacock

feather, Beetle, or Printed Photo (view and draw

only 1 specimen)



Todays Lab

Part C: The Electron Microscope (81)

± Examine the photomicrographs in the packet, to

fill in specimens for Table 3.

± For questions below Table 3, use

photomicrograph (Cat Flea)

± All of this must be checked off before you leavetoday.



Todays Lab

PART D: Clean Up (pg. 74)

± Wash hands

± TU RN OFF ALL SCOPES AND BE SU RE TH EY ARE SE T T OTH E SCANNING (LOWEST) OBJEC T IVE

± Clean all microscope stages

± Rinse all slides with DI water

± Used cover slips go into the Broken Glass Container (NOTIN THE TRASH)

± Transfer pipets can be trashed

± Clean cubbies and throw away any other trash



HOMEWORK

Work on Allelopathy Lab Reports

Read Lichens and the Environment Lab.

Remember Next Week IS AN OUT SIDE LAB

30504344 Environmental Microscopy Power Point

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