There's no such thing as a "universal bottle" in a microbiology lab. It's likely you're referring to a specific type of container used for a particular purpose, but the term is not standard.

To help you, please clarify what you mean by "universal bottle".

For example, are you thinking of:

* Culture bottles: Used for growing microorganisms in liquid media.

* Sterile bottles: Used for storing sterile solutions or reagents.

* Sample bottles: Used for collecting and storing biological samples.

Once you specify the type of bottle, I can explain its function in a microbiology lab.