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.
1. 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 37 o. C for over night or 16 hours in the shaker incubator.
Observations After over night incubation turbidity in the medium observed which shows the growth of bacteria.
Result Control Nutrient Broth medium
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