Why are the bottoms of petri plates labeled rather than the lid?

Answer 1

1) The bottom of the plate contains the agar and your experiment, if the lid gets lost but the bottom is labled you haven't lost any work. If you label the lid and the lid gets lost you won't be able to identify your experiment. You would have to start from the beginning, making plates, sterilizing plates, doing the experiment; perhaps not an option if it were a clinical sample.

2) The plates are placed in the incubator with their bottom half upper most. This is done to prevent droplets of moisture falling from the lid and smearing the culture. As the bottom is upper most when you are looking in the incubator it makes sense to label the bit you can see most easily.

Answer 2

The bottoms of petri plates are labeled to avoid confusion or mix-ups when handling multiple plates. Since the plates are stacked with the bottom facing up, labeling the bottom ensures that the identification remains visible and consistent, even when the plates are stacked.

Answer 3

Petri Dishes are marked on the bottom so that there is no confusion as to the sample number.

Specially when working with patients samples you do not want to mix them up.

As from a quality control point of view petri dishes are marked on the bottom because you can switch the lids.

Answer 4

to make the plate identifiable and the Petri plate would constantly be placed with the label faced upward.

Answer 5

So nothing blocks the view.