types of media

1. Culture Media
Prof. Dr. Ihab Moussa

2. Culture Media
Indications/ Need for culture -
 Isolate bacteria in pure cultures.
 Demonstrate their properties.
 Obtain sufficient growth for preparation
of antigens & for other tests.
 Typing bacterial isolates.
 Antibiotic sensitivity.
 Estimate viable counts.
 Maintain stock cultures.

3. Classification of Media
 Based on the consistency :
Solid media
Semisolid media
Liquid media

4. Classification
 Based on the function or property:
- Simple media
- Enriched media
- Enrichment broth
- Selective media
- Indicator media
- Differential media
- Composite media
- Transport media

5. Constituents Of Media
 Agar or agar- agar
 Peptone - mixture of partially digested
proteins
 Yeast or meat extract
 NaCl
 Melting point : 98°C
 Solidifying point : 42°C
 % of agar : Solid media (2%)

6. Simple Media
 Also called Basal medium
 Most commonly used in routine labs.
e.g. Nutrient broth, NA

7. Enriched Media
 Blood, serum or egg added to the
basal medium.
 To grow bacteria which are more
exacting in nutritional requirements.
e.g. Blood Agar, Chocolate Agar

8. Blood Agar Media

9. Enrichment Broth (media)
 For mixed cultures or materials
containing more than one bacterium.
 Contains substances which stimulates
wanted bacteria & inhibits unwanted
bacteria.
e.g. Tetrathionate broth

10. Selective Media
 Substances added to a solid media to
favour the growth of wanted bacteria.
e.g. MacConkey agar media

12. Indicator Media
 Change in the colour of indicator with
the growth of bacteria.
e.g. Sulphite in Wilson Blair media
for Salmonella typhi.

13. Differential Media
 To bring out differing characteristics
of bacteria.
e.g. MacConkey’s agar

14. Oct 07 Dr Ekta, Microbiology, GMCA
Composite Media
 For identification of
isolates
e.g. Triple Sugar Iron
Transport Media
 For delicate organisms
 Delay in transit
e.g. Stuart’s transport
media