What are the methods of obtaining a pure culture?

Answer 1

One fail safe way to obtain a pure culture is the streak plate method. This is the best of several ways to obtain a PC. Streak plates allow us to isolate a particular microbe from a mixed culture. A small amount of desired microbe is obtained with a sterile loop, and a single colony is grown on a separate quadrant of the agar plate, or ideally another agar plate all together. One advantage to this method is that a skilled student can, if experienced and skilled, recolonize one particular type of bacteria/microbe up to three times on one agar plate, wherefore less materials are used. Another significant benefit is that this is one of the quickest methods.

Another method of obtaining a pure culture is the pour plate method. Pour plating is a method of separating one species of bacteria from another by diluting one loopful of organism into three liquefied nutrient agar plates, with the hopes that one of the plates poured will provide an ideal sample for isolation. An advantage to this method is that it requires far less skill than the first method, however requires far more materials and time.

Answer 2

Pure culture can be obtained through streak plate method, which involves isolating individual bacterial colonies via repeated streaking. Other methods include spread plate technique, where sample is spread over agar surface for isolated colony growth, and serial dilution method, diluting sample to achieve single colonies. Additionally, using selective media can facilitate growth of specific organisms for pure culture isolation.