![Which of the following is used for the proper maintenance and preservation of pure cultures?](https://www.gkseries.com/blog/wp-content/uploads/2022/10/Which-of-the-following-is-used-for-the-proper-maintenance-and-preservation-of-pure-cultures.png)
Q. Which of the following is used for the proper maintenance and preservation of pure cultures?
- Periodic transfer to fresh media
- Preservation by overlaying cultures with mineral oil
- Preservation by lyophilization
- All of the above
Answer: All of the above