To Do Electron Microscopy Lecture Results from Environmental Plates & Broths Serial Dilution & Streak Plates Fungi: make wetmounts & observe demo’s Observe gram stain demo’s/finish old slides
Relative Size of objects
Resolution Analogy
Resolution
Anatomy of a Wave
Properties of Light Wavelength: Length of a light ray; represented by the Greek letter lambda () Equal to the distance between two adjacent crests or troughs of a wave Resolution: Refers to the ability to see two items as separate and discrete units
Properties of Light Resolving Power (RP): minimal distance two points can be distinguished as two points The smaller the distance between objects that can be distinguished, the greater the resolving power of the lens RP= /2(NA)
Microscope Comparison
Modern Scanning Electron Microscope
Limits of Resolution Eye: 0.2 mm = 200 microns = 200,000 nm BF scope: 0.0002 mm =0.2 microns = 200 nm TEM: 0.00001 mm = 0.01 microns = 10 nm Fig. 3.p039
E . coli Brightfield KM
Comparison of Electron Microscopes E.coli SEM E. coli TEM
Resolution vs. Magnification Light Microscope SEM
SEM
TEM
Type of Scope?
Type of Scope?
ID Microbe & Specific Scope CDC, used with permission
Microscope comparison John Wiley
Results from Environmental Samples Learn how to interpret broth culture growth patterns
Broth comparison uninoculated
Various Colored Colonies
Review Properties of Agar Comes from Red algae Microbes usually don’t eat it Not toxic Melts at 100 C Solidifies at 40 C
Preparation of a pure Culture
4 Quadrant Streak Plate 3. loop 2. loop 4. loop 1. swab Do right NOW
Quantitation of Bacteria
Serial Dilutions
Comparison of Serial Dilution Techniques
Pour Plate
Countable number of colonies (20 to 200 per plate) Which of these plates would be the correct one to count? Why?
Serial Dilutions
Fungal Demo’s Gram Stain Demo’s Aspergillus Treponema pallidum Rhizopus Neisseria gonorrhoeae Penicillium Corynebacterium Candida
Aspergillus 100x 400x KM
What are these? KM 400x
Rhizopus 100x KM
Penicillium 100x 400x
Candida 100x 400x KM
Candida & staphylococci KM
Fungal Demo’s Gram Stain Demo’s Aspergillus Treponema pallidum Rhizopus Neisseria gonorrhoeae Penicillium Corynebacterium Candida
Treponema CDC, used with permission
Treponema 1000x KM Wikipedia Commons, used with permission
Diplococci of Neisseria gonorrhoeae (4087X)
TEM diplococci of Neisseria gonorrhoeae (96,051X)
Neisseria 1000x KM
Neisseria 1000x KM
Corynebacterium diphtheria CDC, used with permission
Corynebacterium diphtheria—the cause of diphtheria
Corynebacterium 1000x KM
Fungal Demo’s Gram Stain Demo’s Aspergillus Treponema pallidum Rhizopus Neisseria gonorrhoeae Penicillium Corynebacterium Candida
www.udel.edu
ID Microbe & Specific Scope