Various types of culture media

1. Various Types & Methods Of
Culture Media
Dr. Kanwal Naz

2. • Experiment #
Objective :
To study various types of culture media.
• A culture media is a compound ,which has constituents that are
essential for life, multiplication and growth of a micro organism .
• Ingredients are mixed in a definite ratio at a particular pH according
to the requirement of the micro organism .
• Most organisms grow at pH of 7.2 to 7.6 .

3. Classification According To Consistency:
• Solid Medium  2-4 % Agar
• Semi solid Medium  0.4-0.5 Agar
• Liquid Medium  Broth

4. Classification According to Constituents/Nature:
Basic media:
Nutrient broth
Nutrient agar
Enriched Media:
Chocolate agar
Robertson’s cooked
meat media
BHI
Differential Media:
MC Conkey’s agar
Blood agar
Selective Media:
Lowenstein Jensen
media
Loffler's media
K+ Tellurite media
Transport Media:
BHI
Cary Blair medium

5. Simple media :
• Simple or basic culture media which contain the minimum adequate
nutrition.
• Example:
• Nutrient broth
• Nutrient agar
• Peptone water

6. Enriched media:
• Chocolate Agar: this is a solid enriched medium prepared by heated
blood .
• Used to grow fastidious organisms like:
• Neisseria gonorrhea
• Neisseria meningitides
• Hemphilus Influenza
• Streptococcus pneumonia.

8. Differential media:
• Blood Agar: it is a solid enriched medium
• Constituents:
• Nutrient broth
• Blood and agar.
• Uses:
• Used for growth of various types of microorganisms(gram positive
and G.negative)
• Used for the study of haemolytic criteria of micro organism

9. • B Hemolytic : Complete hemolysis, it will produce a clear zone
e.g. streptococcus pyogenes.
• Alpha Hemolytic: Incomplete hemolysis ,it will produce greenish zone
e.g. streptococcus viridans.
• Non Hemolytic: There is no hemolytic zones e.g. streptococcus
fecalis and enterococcus

11. Mc Conkey’s Agar:
• It can differentiate two groups of micro organisms, in this medium
gram negative bacilli are differentiated into:
1. Lactose fermenters.
2. Non lactose fermenters .
• Constituents:
• Nutrient agar
• Bile salts
• Lactose
• Phenol red indicator

12. Lactose fermenters Non lactose fermenters
Produce lactic acid No fermentation
Decreased PH No decreased PH
Pink colonies Colorless colonies
e.g. E.coli
Klebsiella
Enterobacter
e.g. Salmonella
Shigella
Proteus

14. Selective media:
• It is a special type of medium ,which is selective for particular organisms.
• 1. SS Agar: selective for Salmonella and Shigella
• 2. Lowenstein Jensen Medium: selective for Mycobacterium Tuberculosis.
• Composition:
a) Homogenized whole egg.
b) Malachite green.
c) Penicillin G.
d) Glycerol.
e) Hydrochloric acid.
• 3. TCBS Agar: selective for Vibrio cholerae.

16. Transport media: used to transport of the specimen to keep the
organism alive if inoculation on the culture medium will take time.

17. Experiment # 7
Blood culture:
• Blood culture is the single most important procedure to detect
systemic infections.
• Sepsis
• Endocarditis
• Enteric fever

18. BHI (Brain Heart infusion)
made by boiling cow heart and brain that releases soluble factors into the
broth.

19. Method:
• Collect 5-10 ml blood of the patient and push all the blood in the
medium bottle immediately
• Mix and incubates at 37c for 7 days
• Examine the bottle for turbidity daily and sub –culture on Blood agar
and MC Conkey’s agar after every 2 days and incubate at 37c for 24
hours
• Look for the presence of colonies.

20. Experiment # 8
Anaerobic Culture :
• Some organism can not grow in the presence of Oxygen. they require
Oxygen free atmosphere.
Examples of Anaerobic organisms:
1. Bacteriodes intestinal tract.
2. Fusobacterium gingival crevices
3. Actinomysces israelli
4. Peptostreptococci skin, mouth, vagina,GIT
5. Clostridia species, spores in soil and water.

21. Method:
• 1. Deep culture in Agar: inoculate deep in the agar medium ,apply layer
of paraffin oil covering the liquid medium after inoculation .
•
• 2. Cooked Meat Medium: cook meat with iron particles ,Iron form iron
oxide and most of the oxygen is utilized in the reaction.
• Anaerobic Jar: it’s a jar with airtight lid ,so that no outside oxygen can
enter. oxygen already in jar is removed as follows:
• 1.excess oxygen is removed by a vacuum pump or gas generating kit is
placed.
• 2. chemical reaction absorb the oxygen