Lab equipment

1
Chapter?

• Lab equipment procedures

2
Microscopes

• Light Microscopes
• 1. Single Lens
• 2. Compound microscopes
• eye piece objective Total M
• Low P 10X 10X 100X
• High P 10X 43X 430X
• Oil 10X 97X 970X
• Resolving Power 0.2 um
• ( bare eye resolving power 0. 1mm)

3

• B. U.V. Microscopes
• U.V. light
• Resolving power 0.1 um
• C. Fluorescence Microscope
• Fluorescence dye U.V. Light
• eg. TB. Use auramine (yellow dye)
• D. Phase Contrast Microscope
• For living material, viscosity differences are
  increased.

4
The light microscope
5

• E. Electron Micoscope
• 1. Transmission EM
• use a beam of electrons ( very short
  wavelength)
• Resolving power 0.001 um
• Magnification 100,000 X
• 2. Scanning EM
• electrons strike on the surface (3D)

6
The electron microscope
7
How to Prepare Slides

• 1. Living material
• Hanging drop technique (for movement)
• 2. Stain bacteria
• Basic dye color on charge
• eg. methylene blue
• Acidic dye color on - charge
• eg. nigrosine

8

• Staining Techniques
• a. Simple stain
• b. Gram stain 1884 Christian Gram
• Crystal violet primary dye
• Iodine mordant
• 95 ETOH decolorizing agent
• Safranin counter stain
• c. Acid fast stain
• for mycobacteria

9
The Gram stain (1)
10
The Gram stain (2)
11
Preparation of a Pure Culture

• Colonies
• Pure culture techniques
• 1. Streaking methods
• 2. Liquid dilution methods
• Culture medium
• carbon, nitrogen, minerals and water
• - defined medium
• - undefined medium

12
Method (cont.)

• Isolation-pure Culture
• (Discontinuous Streaking)
• 1. Sterilize wire loop by holding over flame
  until it turns bright orange
• 2. Wait a few seconds, cool loop by lightly
  touching NA
• 3. Take bacteria with loop from sample culture
  and streak on other plate.
• 4. Cover, label, and tape plates.
• 5. Put in incubator at 37C

13
Method (cont.)

• Isolation continuous streaking
• Do the same procedure are
• discontinuous streaking except
• follow a different pattern.

14
Dilutions
15

• Special media
• - carbohydrate media
• - selective medium
• select a certain organisms and inhibit other
  organisms. eg. Bile salt select
  Salmonella and Shigella but no E. coli
• - differential medium
• eg. Blood agar
• - enrichment cultures
• eg. Isolate organisms from environment such
  as soil or pond water
• mineral medium sodium benzoate select
• Pseudomonas.

16
Viable counting
17
Turibdimetric growth measurements(1)
18
Turibdimetric growth measurements(2)
19
Turibdimetric growth measurements(3)
20
Bacterial morphologies (1)
21
Bacterial morphologies (2)
22
Bacterial morphologies (3)
23
Bacterial morphologies (4)