If you ever find yourself working in an infectious disease laboratory, whether it’s of the diagnostic or research variety, the overarching goal is not to put any microbes in your eye, an open wound or your mouth. Easy enough, right? Wear gloves, maybe goggles, work in fume hoods and don’t mouth pipette. When working with pathogenic bacteria and viruses, priority number one is Do Not Self-Inoculate.
Former Centers for Disease Control (CDC) parasitologist, Dr. Mae Melvin (Lt), examines a collection of test tubes while her laboratory assistant mouth pipettes a culture to be added to these test tubes. Source: David Senser/CDC.
This is obvious for anyone who has worked in a shiny biology or chemistry lab or seen an episode of CSI: Crime Scene Investigation (we’re all friends here, just admit it), but one of the most commonly used pieces of equipment in labs prior to the 1970s was the leading cause of laboratory-derived infections: the honorable pipette. How could that be possible, you ask? By using one’s oral cavity with the pipette to measure and transfer liquids.
Today our manual pipettes are rather sophisticated, plastic-y devices perfectly calibrated for moving precisely exact milliliters, microliters and picoliters of valuable solution from one vessel to another, whether it’s of a urine sample, some spare radioactive material you have lying about or toxic solvents. But before the development of cheap mechanical pipettes in the ’70s, using your mouth to pipette solutions was more than a common sight, it was a way of the lab.
