Arnaiz, Angel S.
March 25, 2022
BSN-1-B-7
Mrs. Marie Vonne Venus
MICP LAB # 5: CULTURE MEDIA
Chocolate Agar
- A type of nutrient medium
that is used for the culture of
fastidious organism such as
Haemophilus sp. Heat is
applied to lyse the red blood
cells, causing the medium to
turn brown.
Culture Media
- Staining procedures only give
clues as to the probable
organism being studied. To
identify a specific organism,
culture using specific culture
media is the most ideal.
Media (sing, medium) are
used to grow microorganism.
A culture medium is basically
an aqueous solution to which
all the necessary nutrients
essential for the growth of
organism are added. These
are classified into three
primary levels: physical
state, chemical composition,
and functional type.
Dorner, Schaeffer, Fulton Stain
-
Dorner stain utilizes carbol
fuchsin as primary stain, acid
alcohol as decolorizer, and
nigrosin as counterstain. It
employed a lengthy heating
step but resulted in
differential staining of
endospores and vegetative
cells in the same sample.
-
The Schaeffer–Fulton stain is
a technique designed to
isolate endospores by
staining any present
endospores green, and any
other bacterial bodies
red.[1] The primary stain
is malachite green, and the
counterstain is safranin,
which dyes any other
bacterial bodies red
Dyer Stain
- A dye is a general-purpose
coloring agent, whereas a
stain is used for coloring
biological material.
Fisher Conn Stain
- was used to obtain stains of
10 cultures of marine
agarolytic bacteria
(tentatively placed in the
genus Alginomonas). All had
a single polar flagellum.
Flagella on cells grown in a
synthetic medium were
easily demonstrated with
little stained background. A
brief discussion of
flagellation as a taxonomic
criterion of the agarolytic
bacteria is included.
Hemolysis: Alpha, Beta, Gama
Alpha hemolysis- shows incomplete
lysis of red blood cells, producing a
greenish discoloration of the blood
agar around the colonies.
Beta hemolysis- shows complete
lysis of red blood cells resulting in
complete clearing around the
colonies.
Gamma hemolysis- shows no
hemolysis, resulting in no change in
the medium.
Hiss Stain
- a type of positive staining
method that stains the
capsule and the bacterial cell
with a brighter background.
For the reason that a capsule
appears as a light violet color
between a dark violetcolored bacterial cell and
colorless background.
India Ink
- India ink capsule stain is
used to demonstrate cell
capsules through
microscopic examination.
This procedure is used to
detect presence of
encapsualted species, e.g.
Cryptococcus neoformans,
which causes cryptococcosis
in humans
Kinyoun Method
- Also known as the “cold
method” as it does not utilize
heat after addition of the
primary stain, which oil
based. The acid-fast
organism will appear red on
a green background.
“Lamb” Loeffler Alkaline Methylene
Blue
- is suitable for staining and
monitoring genera such as
Gonococcus, Lactobacillus
and for visualizing genus
Pasteurella. It is also suitable
for staining bacterial nucleus
and cytoplasm. Methylene
Blue Loeffler reagent is
slightly toxic. It can cause
cell mutation in very high
doses.
Lowenstein- Jensen Medium
- A selective medium used to
recover Mycobacterium
tuberculosis. It is made
selective by the incorporation
of malachite green.
Macconkey Agar (Mac)
-
Promotes the growth of
gram-negative bacteria,
primarily those belonging to
the family
Enterobacteriaceae, and
inhibits the growth of grampositive bacteria through the
addition of bile salts. It is
both selective and
differential.
Media: Liquid, Semi-solid, Solid
Liquid media- these are waterbased solutions that do not solidify
at temperatures above the freezing
point. These contain specific amount
of nutrients but do not contain
gelling agent such as gelatin or
agar. Liquid media are suited for the
propagation of large number of
organisms, fermentation studies,
and other tests.
Semi-solid media- exhibit clot-like
consistency at an ordinary room
temperature and contain agar at
concentration of 0.50% or less that
allows thickening of media without
producing a firm substance. They
have soft consistency similar to
custard and are best suited for
culture of microaerophilic bacteria
or for the study of bacterial motility.
Solid media- contain a solidifying
agent such as 1.5%-2% agar, giving
them a firm surface on which cells
can form discrete colonies. They are
used for isolation of bacteria and
fungi or for determining the colony
characteristics of the organism
under study
Sabouraud Dextrose Agar (SDA)
- Sabouraud Dextrose Agar
(SDA) is a non-selective
isolation medium used for
the growth and maintenance
of pathogenic and nonpathogenic fungi from clinical
and nonclinical specimens. It
is also used for recovery and
total counting of yeasts and
moulds in environmental
monitoring.
Special Staining
- These are used to
demonstrate specific
structures in a bacterial cell.
For instance, metachromatic
granules can be visualized
using the LAMB( Loeffler
Alkaline Methylene Blue)
stain.
Thayer- Martin Medium
- Contains the antibiotics
trimethoprim, nystatin,
vancomycin, and colistin. It is
used for the isolation of
Neisseria.
Ziehl-Neelsen (Zn)
-
Also known as the “hot
method” because it requires
steam-bathing the prepared
smear after addition of the
primary dye. This is because
the primary stain used is
aqueous and will not bind to
the cell wall of the organism.
Acid-fast organisms will
appear red on a blue
background.