Effective maintenance of stock cultures is essential for QC, method validation and research purposes
Repeated subculturing may eventually lead to contamination, loss of viability and genotypic/phenotypic changes
Freeze-drying and cryogenic storage are preferred, but may not be practical for smaller laboratories
Cryoprotectant beads allow routine labs to maintain a stock culture collection simply and at low cost.
Pure cultures are important in Microbiology for the following reasons:
Once purified, the isolated species can then be cultivated with the knowledge that only the desired microorganism is being grown.
A pure culture can be correctly identified for accurate studying and testing, and diagnosis in a clinical environment.
Testing/experimenting with a pure culture ensures that the same results can be achieved regardless of how many time the test is repeated.