Download Aim : To perform the Sub culturing of Bacterial

Aim : To perform the Sub culturing
of Bacterial Culture.
Principle
Sub culturing is the term used to describe the procedure
of transferring of microorganisms form their parent
growth source to a fresh one or from one medium to
another. After incubation has been completed in streakplate, pour-plate, or spread-plate techniques and appearance
of the discrete, well separated colonies has examined. The
next step is to subculture the cells from one of the colonies to
separate agar plates with a sterilized needle or loop for further
examination and use. Each of these new culture represents the
growth of a single species and is called a pure or stock
culture. When the transfer is done form a solid medium
(agar) to liquid medium(broth), the term picking off is
used. This technique is also used routinely in preparing and
maintaining stock cultures.
Requirements :
 Nutrient agar streaked bacterial plate
 Nutrient Broth Medium
 Inoculating needle
 Sterile test tube with cotton plug
 Bunsen Burner
 70 % ethanol
 Shaker Incubator
Procedure :
1. Sterilize the inoculating needle by holding
it in the hottest portion of the Bunsen
burner flame.
2. Flame until the entire wire becomes red
hot.
3. Allow the loop to cool for few seconds.
4. Touch the tip of the needle to the surface of
a selected discrete colony on the agar
streak plate.
Take the 5 ml of nutrient broth medium in to the
test tube.
2. Add the bacterial cells in to the liquid media by
dipping the inoculating needle to the media.
3. Reflame the inoculating needle to destroy
existing organisms.
4. Incubate the cultures (in test tube) at 37oC for
over night or 16 hours in the shaker incubator.
1.
Observations
After over night incubation turbidity in
the medium observed which shows the
growth of bacteria.
Result
Control Nutrient
Broth medium
Control Nutrient
Broth medium