Bacterial culture methods
It is a method of multiplying microbial organisms by letting them reproduce in a pre-determined culture medium under controlled laboratory conditions. Types-
. Liquid Culture (broth culture):
Liquid media is poured in a tube, on which pure bacterial colonies are inoculated.
Tube is lightly swirled in circular motion for proper mixing; let it grow (incubate) overnight and sub-cultured further in appropriate medium
. Solid Culture:
On a well-labelled petri-plate containing agar medium (like NA), a loopfull of bacterial colony is inoculated using an inoculating loop forming a well.
Quickly and gently steak four parallel lines across the agar from the well, with proper flaming of loop.
Drag the loop 4 times, hitting through the area you just streaked. Turn the plate 90 degrees. Repeat the procedure and fill in the remaining area of the plate, slightly hitting the area previously streaked (with flaming the loop after each streak)
turn the petriplate upside down to prevent moisture running onto the agar medium.
Place the inverted plate in a 37°C incubator overnight (24hrs); Observe the plate the following day.
. Stab culture: Stab cultures are similar to agar plates, but are formed by solid/semi solid agar in a test tube. Bacteria is introduced via an inoculating wire being stabbed into the center of the agar. Bacteria grow in the punctured area.
