1. BDS 2ND YEAR OSPE
SLIDES 2011
DR EJAZ WARIS
Associate Professor
Histopathology FMHC

6. Chocolate agar
 Chocolate agar (CHOC) - is a non-selective,
enriched growth medium.
 It is a variant of the blood agar plate.
 It contains red blood cells, which have been
lysed by heating very slowly to 56 °C.
 Chocolate agar is used for growing fastidious
(fussy) respiratory bacteria, such as
Haemophilus influenzae.
 These bacteria need growth factors, like NAD
and hematin, which are inside erythrocytes;
thus, a prerequisite to growth is lysis of the red
blood cells

9.  A nutrient culture medium that is enriched with whole
blood and used for the growth of certain strains of
bacteria.
 Contains mammalian blood (usually sheep or horse),
typically at a concentration of 5–10%.
 BAP are an enriched, differential media used to isolate
fastidious organisms and detect hemolytic activity.
 β-hemolytic activity will show complete lysis of red blood
cells surrounding colony, while α-hemolysis will only
partially lyse hemoglobin and will appear green. γ-
hemolysis (or non-hemolytic) is the term referring to a
lack of hemolytic activity.

11. micropipette
A pipette used to measure very small
volumes of liquids.

13.  Elisa microtitre plate

17.  Salmonellashigella agar plate with h2s
producing colonies

26.  The Lowenstein-Jensen medium, popularly
known as LJ medium, is a growth medium
specially used for culture of Mycobacterium,
notably Mycobacterium tuberculosis.
 When grown on LJ medium, M. tuberculosis
appears as brown, granule-like colonies.
 The media must be incubated for a significant
length of time, usually four weeks, due to the
slow doubling time of M. tuberculosis compared
with other bacteria (15-20 hours).

43.  Cysteine
Lactose Electrolyte Deficient agar (CLED)
 CLED agar is used to isolate and differentiate
urinary tract bacteria, since it inhibits Proteus
species swarming and can differentiate
between lactose fermenters and non-
fermenters.

57. MacConkey agar (MAC)
A selective and differential media used to
differentiate between Gram negative bacteria
while inhibiting the growth of Gram positive
bacteria.
 The addition of bile salts and crystal violet to the
agar inhibits the growth of most Gram positive
bacteria, making MacConkey agar selective.
 Lactose and neutral red are added to
differentiate the lactose fermenters, which form
pink colonies, from lactose nonfermenters that
form clear colonies.

68.  Sabouraud agar is used to culture fungi
and has a low pH that inhibits the growth
of most bacteria;
 also contains the antibiotic gentamicin to
specifically inhibit the growth of
Gram-negative bacteria.

70.  TripleSugar Iron medium is a differential
medium that can distinguish between a
number of Gram-negative enteric bacteria
based on their physiological ability (or lack
thereof) to:
 a. metabolize lactose and/or sucrose
b. conduct fermentation to produce acid
c. produce gas during fermentation
d. generate H2S.

71.  The medium contains 1.0% each of sucrose and lactose
and 0.1% glucose.
 If only glucose is fermented, acid produced in the butt
will turn it yellow, but insufficient acid products are
formed to affect the methyl red in the slant.
 However, if either sucrose or lactose are fermented,
sufficient fermentation products will be formed to turn
both the butt and the slant yellow.
 If gas is formed during the fermentation, it will show in
the butt either as bubbles or as cracking of the agar.
 If no fermentation occurs (as for an obligate aerobe), the
slant and butt will remain red.