Water droplets can form on the lid due to temperature changes and fall on the agar, which can:

➡️ Spread the bacteria unintentionally 🦠

➡️ Cause swarming or mixing of colonies

➡️ Lead to inaccurate results such as counting in enumeration test ❌

Why do we incubate fungal plates upright (lid up)?

For fungal cultures, we keep the plates upright (normal position) because fungal spores are extremely light! If the plate is inverted:

➡️ Spores can fall on the lid

➡️ Provide humidity for fungal growth

➡️ Decrease the risk of cross-contamination in the Incubator 🚫

Also, fungal colonies are usually larger and taller, especially the filamentous ones.
They need gravity or vertical space to grow and develop their natural fruiting bodies 🍄🌱

Reference:
https://lnkd.in/gXDC9QrD