Compound Light (Brightfield) Microscope
Type of microscope where only light NOT scattered by the specimen enters the objective
What does a Light (Brightfield) Microscope require?
Requires both staining and heat fixation
Phase-Contrast Microscope
Type of microscope that condenses both scattered and non-scaattered light to enter objective
Advantages and Disadvantages of Phase-Contrast Microscope
Advantages: Observe true morphology of living cells (cells are not stained and heat fixed) and Increased resolution of cells | Disdvantages: Cost
Darkfield Microscope
Type of microscope which only allow light scattered by the specimen to enter the objective, not the beam of light coming directly from the condenser
Advantages and Disadvantages of Darkfield Microscope
Advantages: Study living organisms; study true morphology | * Disadvantages: Cost
Electron Microscope
Type of microscope that can enlarge an image up to 1,000,000 X.
Magnification of Ocular/Eyepiece Lens
10X
Magnification of Oil Immersion Objective Lens
100X
Magnification of High Dry Objective Lens
40X
Magnification of Low Power Objective Lens
10X
Total Magnification
Objective Lens X Ocular Lens
Nose Piece (Microscope)
Holds objective lenses and rotates
Iris Diaphragm (Microscope)
Controls the size of illuminated field of vision on the specimen | * Controls the amount of light hitting the specimen
Condenser (Microscope)
Group of lens under the stage that condenses the light source on specimen | * Controls amount of light hitting specimen
Coarse Focus Adjustment Knob (Microscope)
Used only for low power (10X) objective to adjust distance of stage to objective lens
Fine Focus Adjustment Knob (Microscope)
Use to find focus objective lenses
Parfocal Design (Microscope)
Once objective is in focus, the remaining objectives will also be in focus
Focal Length (Microscope)
Length of the objective lens
Mechanical Stage and Stage Clips (Microscope)
Holds and supports slide
Mechanical Stage Control Knobs (Microscope)
Used to adjust position of slide while viewing
Arm and Base (Microscope)
Used to carry microscope
Resolving Power
Ability to distinguish two adjacent points
Resolving power of oil immersion objective lens
0.2 Microns
Resolving power of human eye
0.1 Microns
Numerical Aperture
Mathematical expression of the solid cone of light delivered to the specimen by the condenser and gathered by the objective |
Higher Numeral Aperture, better Resolving Power (Resolution)
Ways to Improve the Resolving Power
Increase the Numerical Aperture |
Oil |
Open Diaphragm |
Use Shorter Wavelength of Light
Blue-Violet Range
490 nanometers
Blue-Violet Filter
Absorbs all other wavelengths of light
Diplococcus
Cocci in pairs
Monotrichous Flagella
Flagella on one end
Amphitrichous Flagella
Flagella on both ends
Lophotrichous Flagella
Tuft of Flagella
Peritrichous Flagella
Flagella all over surface
Atrichous
No Flagella
Saprophyte
Microbes in nature which breakdown decaying organic material into inorganic material |
Function is to recyle nutrients in nature
Opportunistic Organisms
Microbes that will cause disease in humans under proper condtions
Proper Conditions for opportunistic organisms
Proper Portal of Entry (Tissue Affinity) |
Virulance Factor (Toxins, capsules) |
Proper number of organisms (Dosage) |
Lowered Host Resistance (Poor diet, stress, other diseases)
Obligate (Strict) Pathogens
Disease producing microbes not generally found outside the human body
Colony
Composed of billions of cells that originate from one parent cell
Chromogenic
Produces pigment
Aseptic Technique
Prevent cross contamination
Agar
A solidifying agent not a nutritional source | * Composed of a carbohydrate derived from an algae
Agar % of solid media
1.50%
Agar melts at what temperature?
100C
Agar solidifies at what temperature?
42C
pH level of Sabouraud Agar
pH 5.6
pH leve of Nutrient Agar
pH 7.2
Optimal pH of Fungi
pH 5 to pH 6
Optimal pH of Bacteria
pH 6.8 to pH 7.4
Fastidious Microbes
Requires growth factors such as Vitamins, Blood, Minerals
Ubiquity of Microbes
Microbes are abundant and found everywhere in our environment
Room Temperature
25C
Bacterial Morphology
Cocci (Single, Chains, Paired, Clusters) |
Rods (Single, Chains) | * Spiral-Shaped