"How does this work?" you might ask. Well, laboratory professionals would use their own mouth to suck up a specific amount of specimen. This could be blood, urine, or a variety of other specimen. There is no way this was safe practice. The specimen could easily be sucked into the mouth on accident and possibly swallowed. This could cause infection to the lab technician. According to Phillips , a survey in 1915 of 57 labs showed that there were 47 infections associated with workplace practices, and 40% of these were due to swallowing a corrosive or toxic substance or an infectious specimen (1966). As you can imagine, this technique of pipetting was abandoned once mechanical ones were invented to take their place. Phillips also thought it was necessary to outline the simple rules to follow:
1. Do not mouth pipette infectious or toxic fluids.
2. Use a pipettor device for pipetting.
As developing scientists in the 21st century, we look at these rules and think they are blatantly obvious. Overall, I think it is really cool to see where we have come in science and how a few decades ago people thought this was an acceptable practice.
Here is the link for the article published in 1966:
http://www.dtic.mil/dtic/tr/fulltext/u2/640356.pdf
Kelsey-
ReplyDeleteAfter committing to SHSU, I told some of my parent’s friends that I would be attending graduate school for forensic science, specifically toxicology. I continued to explain different methods used in toxicology, including pipetting bodily fluids. One of my parent’s unscientific friends proceeded to tell me to be careful pipetting because he once pipetted acid into his mouth! He had pipetted by mouth when he was in school. I was shocked! Could you imagine using your mouth to pipette concentrated HCl, diseased blood, or that smelly β-mercaptoethanol from last week’s lab? I, too, had never known that mouth pipetting existed until he told me that story. I made sure to explain to him about the newest and greatest micropipetting technologies. It is amazing to see the evolution of science methodologies over time!
I have seen mouth pipetting listed as a precaution several times in notebooks for classes but I always thought of it as a joke. It's hard imagine that people once had to do this for measurements at some point in time but it kind of makes sense for them to do it since they did not have the equipment that we do now. Don't get me wrong, this technique is still dangerous and as you emphasized, they could get an infection or contaminate their samples. My question to you is: Do you know if the practice of mouth pipetting still goes on today anywhere in the world?
ReplyDeleteI also used to see those warnings of not pipetting with you mouth, and never knew why it was listed. To me it is completely mind blowing how mouth pipetting was a thing. I could not imagine ever doing that. It is also crazy that 40% of the infections were associated with workplace, and it is wonderful how far we have come today.
ReplyDeleteSometimes I look at the work done by scientists from back in the day and think "Wow, I wish I was that smart," then I read things like this. HOW could anyone think this was ok? I get that not as much was known back then, but I'm pretty sure most people knew that getting acid in your mouth would be bad. Or worse, PEE!
ReplyDeleteEvery lab manual that I've had has made it very clear that mouth pipetting is not allowed. I always thought that this was an obvious thing for obvious reasons. I could never imagine mouth pipetting anything at all. Especially not bodily fluids or specimen! I am not surprised that so many labs reported infections because of the workplace techniques.
ReplyDeleteI worked for a while with an old pathologist who mouth-pipetted...anything. Blood, organic reagents, you name it. It used to confuse the crap out of me because there was a perfectly useable serological pipette on the bench right in front of him.
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