How to supply oxygen to a culture vessel?

Question

I'm reading this paper: https://www.jstage.jst.go.jp/article/jpsa/51/3/51_0130043/_pdf

From day 17 of the culture period until hatching, pure oxygen was supplied at a flow rate of approximately 500 ml/h through the previously installed plastic tube.

What kind of hardware is used to achieve this ? I would like to test this method, but I don't have access to laboratory equipment ( meaning .. I'm not going to buy expensive equipment for this hobby project..)

I'm used to incubate eggs inside an incubator, and day 17 is approximately the day when they start chirping, and sometimes hatching, so it's my understanding that at this point the chick starts to use its lungs, and breaks the shell in search of oxygen.

Also I don't understand the airflow in this setup: when I supply 500 ml/h of oxygen, where does the displaced gas go ?

Answer 1

Gases are supplied to culture vessels by design. Flasks, for example, may have filtered caps that allow gas in, or microplates with lids that have enough room under the lid to allow a gas exchange interface with the culture medium. Of course with these traditional culture vessels you need to make careful consideration about fill volume, since the gases won't penetrate 100% through the culture medium.

In the case of your paper they cut a large hole in the side of the cup and plugged it with cotton, then fed a small plastic tube through into the cup. They attach a gas line and feed oxygen through the tube. The cotton plug is where the gas will escape back out without letting contaminants in, as the cotton plug acts as a filter. The system seems to have no other outlet, so it makes sense.

In order to control a gas flow rate, you need a regulator of some sort to act as an output control.