Aim – To prepare the sub-culturing of bacteria and fungus.
Requirement – Mixed nutrient agar streaks, Nutrient agar slants or nutrient agar plates, Inoculating loop, Wax marking pencil, microscope
Theory – Following streak plate, pour plate, or spread plate incubation and examination of the appearance of the distinct, well-separated colonies, the next step is to subculture some of the cells from one of the colonies to separate agar plates or nutrient agar slants with a sterilised needle or loop for further analysis and use. One species known as a pure culture or stock culture is represented by each of these new cultures, which is the expansion of that species. Transferring microorganisms from one medium to another or from one parent growth source to a fresh one is referred to as subculturing.
Procedure –
- With a wax pencil label the nutrient agar slants and agar plates as bacteria A & B. Sterilize the inoculating loop by holding it in the hottest portion of the Bunsen burner flame.
- Flame until entire wire become red hot.
- Allow the loop to cool for a few seconds or cool it by dipping in a fresh agar plate.
- Touch the tip of the loop to the surface of a selected discrete colony or the agar streak plate or the pour plate.
- Remove the plug of the agar slants, grasp the plug with thee little finger of the left hand and pass the neck tube rapidly over the Bunsen burner flame. Inset the loop into the subculture tube rapidly over the Bunsen burner flame. Inset the loop into the subculture tube and inoculate it lightly over the hardened surface in a straight or zig zag line and recap tube.
- Reflame the inoculating loop/ needle to destroy existing organism.
- Incubate the culture for 48-72hrs.
Result – The sub-culturing of bacteria and fungus was prepared.
