Which practice is recommended for large culture tubes when preparing fungal cultures?

• A. Poured in thick slants
• B. Screw down cap tightly
• C. Store upright in bright light
• D. Shake vigorously before inoculation

Answer: (A)

Pouring a thick slant is recommended because the thickness of the agar in a culture tube matters for moisture retention and available surface area, especially in larger tubes. A thicker slant keeps the surface moist longer and provides ample space for the fungus to establish growth after inoculation, which helps maintain viability during incubation and handling. In large tubes, the risk of drying out is greater, so a thicker slant helps prevent desiccation and supports better initial colonization.

Choosing to screw the cap down tightly would limit gas exchange, which many fungal cultures need to grow properly. Storing the culture upright in bright light is not ideal because light exposure can stress or degrade cultures over time. Shaking vigorously before inoculation would disrupt the surface of the agar and spread contaminants, hindering a clean, uniform growth.