Transcript ERT 144 microbiology week4

Week : 4 .ERT 144
staining (rev, quiz)
isolation & identification
Preparations of Specimens for
Microscopes
simple
Fresh
Preparation
Positive
Gram
Acid Stain
Differential
Staining
Spore
special
Capsule
Negative
Flagear
safranin
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Malachite green
Congo Red
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Mycobacterium tuberculosis
Mycobacterium Leprae
24 years old man infected with leprocy
gram
simple stains require only a single dye and a simple uncomplicated
procedure,
differential stains use 2 differently colored dyes : primary dye and the
counterstain,
Special stains are used to emphasize certain cell parts that are not revealed
by
conventional
• simple
staining staining
uses themethods
ready binding of bacterial cells to dyes like malachite
green,
crystal violet, basic fuchsin, and safranin.
•It reveals bacterial characteristics such as shape, size, and arrangement
•all cells, regardless of type, appear almost the same color
Gram staining (Hans Christian Gram ) :
Universal diagnostic staining technique for bacteria.
gram-positive, >stain purple
gram-negative, >stain pink (red).
is the basis of important bacteriological topics eg taxonomy, cell wall
structure,
The different results in the Gram stain are due to differences
in the structure of the cell wall (peptidoglycans) and how it
reacts to the series of reagents applied to the cells.
Gram Staining
tr
Streak plate
D