Question

The preservation of agar slopes has an expiration of 6 months and the agar needs to be changed every 6 months. Which of the following can be used to extent sub-culturing to 1 year?

(a) Paraffin oil

(b) DMSO

(c) Glycerol

(d) Loamy Soil

The question was posed to me in an interview for internship.

This interesting question is from Preservation of Industrial Microorganisms topic in section The Isolation, Preservation and Improvement of Industrial Microorganisms of Fermentation Technology

Answer 1

Correct choice is (a) Paraffin oil

Easiest explanation: The agar slants can be covered by paraffin oil and the extension time can be increased from 6 months to 1 year. DMSO, Glycerol, Loamy soil are used in the preservation techniques for the preservation of microbes more than decades.