pure culture vs mixed culture determination How to use colon

pure culture vs. mixed culture determination; How to use colony morphology (such as pigmentation) to examine culture purity? How to isolate pure cultures from a mixed culture? (common techniques)

Solution

Every perticular single pure microorganism must produce its unique pigment. So, in order to examine the purity of culture, the colour of pigmentation during colony morphology should be checked and it can be very helpful in deciding whether the culture is pure or not. For example M. luteus ( Micrococcus luteus) produce carotenoids pigment so form yellow colonies on Nutrient agar. Thus during confirming colony morphology, if the yellow coloines found, it may be pure culture of M. luteus.

There are following commons techniques for the isolation of pure culture from a mixed culture:-