1. Aim: To prepare pure culture by streak plate method.

2. Theory:
Generally bacteria exist in mixed population. It is very rare to get a single and pure form. For studying the cultural, morphological and physiological characters of an individual species it is essential to separate them from the others to get in the form called pure culture . There are many important methods for isolating pure culture from mixed culture like streak plate method, pour plate methods etc.

3. Requirements :
Tripod and wire gauze
Bunsen burner
Beaker of water
Inoculating loop
Nutrient agar
Sterile Petri dish
Mixed culture

4. Procedure:
Liquefy a tube of nutrient agar and pour into the petridish, rotate the plate gently for uniform distribution of the medium.
Streak the plate following quadrant or radiant or T-streak or continuous streak .
Keep the streaked plates in inverted position at 37°C for over night (approximately 16 hrs).
Place the petri dish upside down to solve the problem of water condensation because if it drops down on the colonies , the organisms of one colony can spread on the other colony.

5. Results:
The isolated colonies of desired microbes (at the site of last streak) on the plate will be observed.