MICROPARA Flashcards
use light source & set of lenses to magnify an object
Light Microscope
use a beam of electrons by a system of magnetic fields
Electric microscope
use a laser light to illuminate one plane of a specimen at a time
Confocal
How many dimensions in confocal microscope
2-and 3-dimensional images of cells for biomedical applications
use a sound wave of specific frequency that travels thru the specimen with a portion
being reflected when it hits an interface within the material.
Scanning acoustic microscope
In scanning acoustic microscope, to examine living cells attached to another surface,
cancer cells, artery plaque,
and biofilms.
use a thin material probe that scans a specimen and produces an image revealing bumps
and depressions of the atoms on the surface of the specimen. Resolving power much
greater than EM and no special preparation required
Scanned-probe Microscopes
Types of microscopy
Bright Field Microscopy, Dark-Field Microscopy, Fluorescence Microscopy, Phase-contrast Microscopy, Electron Microscopy
Bright Field Microscopy
Magnification:
Appearance to specimen :
Useful application
1000-2k
Stained color
Gross morpho - bacteria yeast molds algae and protozoa
Dark field microscopy
Magnification:
Appearance to specimen :
Useful application:
1-2k
Unstained lighted
Living state and fluid suspension
Fluorescence microscopy
Magnification:
Appearance to specimen :
Useful application:
1-2k
Bright and colored
Fluorescence dyed fixed to reveal identity
Phase contrast Magnification:
Appearance to specimen :
Useful application:
1-2k
Degress darkness
Cellular structures
Electron MicroscopyMagnification:
Appearance to specimen :
Useful application:
200k-400k
Viewed on fluorescence screen
Virus & ultrastructure of microbial cells
suspends living microorganisms in a drop or film of
liquid
Wet-Mount and Hanging-Drop Techniques
involves drying & staining a thin layer of the
specimen for easy viewing
Staining techniques
3 staining methods
Simple, differential, negative
uses a single dye to stain bacteria or other microorganisms
■ Stains cells uniformly
Simple staining
Uses more than one dye to stain microbial cells or parts of cells
■ Able to show differences between microbial cells or parts of cells
Differential
for the bacterium causing tuberculosis
(Mycobacterium tuberculosis)
Acid fast staining
used to stain specific cellular structures that are
not usually stained by Gram staining (e.g.
endospore-, flagella- & capsule-staining)
Structural
Steps in Preparation of Stained Microbial
Specimen for Microscopic Examination
Preparation of
Smear
Fixation by
heat
Staining with
one or more
dyes
Microbial cells are unstained and made visible because the
background is dark
■ Specimen mixed with India ink and spread into thin film
Negative staining
Informations Used to
Characterize Microorganisms
*Morphological characteristics
■ Nutritional & cultural characteristics
■ Metabolic characteristics
■ Genetic characteristics
■ Pathogenic characteristics
■ Antigenic characteristics
the ability to cause disease
Pathogenic
the ability to elicit antibody formation
Antigenic characteristics
Categories of microscope
Leccs
