To prepare and sterilise Beef Extract Culture Media

To Prepare and Sterlise Beef Agar Culture Media.

Requirements:

• Agar  15g
• Peptone. 5g
• NaCl.  5g
• Beef extract  3g
• Distilled water q.s. to produce 1000ml

Procedure:

1. Take a sterilized beaker. Add 200ml of water and 15g of agar powder.
2. Heat the mixture on the hot plate till the agar dissolves completely in it. It may require to reach at 80-90°C temperature of mixture.
3. Allow to cool the mix. When it comes to 60-70°C add and dissolve beef extract in it.
4. Now add and dissolve Peptone and NaCl in it.
5. Maintain the pH at 7.4 using 5% NaOH solution.
6. Heat the mix at 60-70°C for about 5-10 minutes.
7. Using autoclave sterilize the prepared culture.
8. After sterilisation pour agar culture in petry dish and allow to cool.

Application of different ingredients

Peptone: It provide proties nutrition so that bacteria can grow on it.

Agar: It provide viscosity to the culture media.

Beef extract: It has many water soluble organic nutrition from animal tissue like organic nitrogen compound, carbohydrates, salts and vitamins-minerals. It is the main source of organic nitrogen for growing bacteria.

NaCl: It maintain the electrolyte osmolarity in the culture media.

Precautions:

1. Do not heat the culture media above 70°C.
2. Use sterilized glassware.
3. Always use gloves and facemask.
4. Do not dispose the culture media in the flush, dump it in soil.