They are using their mouths to suck liquids into pipettes. It was an old and dangerous lab technique.
Use a rubber bulb on the end of the pipette. That way your
cartel memberslab techs are safe.We still use mouth in secondary school. I guess its same in undergraduate degree too. But yeah we only take the base in acid-base titration in pipette
Jesus Christ. 20 years ago my chem teacher used to tell me about the bad old days of having to do this, that it's still happening today is horrifying.
I am a bit concerned everyone is just mentioning the squeeze rubber ball thing, maybe because its time appropriate for the images.
But in modern times people should use something like this https://www.integra-biosciences.com/global/en/pipette-controllers/pipetboy-acu-2
Basically it took many years before someone developed something that could be run with a trigger or button. Before that you used a vacuum (your mouth) to pull liquid into a pipette. Heard an older chemistry professor talk about a colleague who years before swallowed a salmonella sample by accident. A lot of people surely got hurt this way.
