Watch any TV story or documentary that deals with medical research or testing and you are bound to see a shot of a set of identical nipples dispensing some liquid into a set of receptacles (e.g., 3rd segment of 60 minutes on 6/28/20). Sometimes it is a set of 5 or 6 nipples in a straight line being manipulated by a researcher, and sometimes it is a 2-dimensional array of nipples being controlled by a machine, but this shot is seemingly obligatory in these stories.
First reply nailed it. Back before auto pipettes, people pipetted by hand. Before that, mouth pipetting (like sucking on a straw) was common. Imagine mouth pipetting caustic or infectious material!
I remember getting a mouthful of gasoline when siphoning from my car into my lawnmower once. I’m certainly glad that wasn’t hydrofluoric acid (or a malaria culture) in a lab!
You see these a lot on the news to; this and autosamplers. The reason is pretty mundane and obvious…it’s the only thing that can be seen doing something. Most everything else is a stationary box that just sits there being boring. Its hard to take interesting footage of tan colored boxes that don’t move. They don’t even go “ping!”
Try this: “If TV is so inept at showcasing anything deeper than an explosion or an argument, then it’s no wonder people raised on by TV think life is nothing but explosions and arguments.”
We used to have an expensive pipetting robot that we couldn’t get to do anything useful set up to endlessly move colored water around its deck for when VIPs wandered in.
I have mouth Pipetted many chemicals in college and later in labs and I think the risks are overstated. Unlike a gasoline siphon, the Pipette has a very thin ID and there is a bulb in the middle to hold the liquid.
When pipetting, you apply suction and watch the bulb fill up whence you slow down and gently continue to fill to the mark.
You don’t Pipette strong solutions. Maybe 1N solution or something close by, it is not that dangerous.
hudrofluoric acid reacts with glass, so glass Pipettes are not used anyways
Places still pipette by mouth? In the last 40 years, I have never worked in a lab that pipetted by mouth; this was a quick way to get a visit from the Safety Officer. Pipette bulbs have been around for more than 45 years - just from personal experience.
(I’m not doubting that there are still places that pipette by mouth; it’s just… blech.)
Every (U.S.) university lab I’ve worked, mouth pipetting would be a you’re-to-stupid-to-be-here boot out the door. Poking around online, I’ve seen some mention of it still occuring in like Pakistan and Nigeria.
Actual working labs, I have no doubt it would be verboten. 1st year chem class, very much not so. Mostly since we were just using pipettes to transfer distilled water for volumetric dilutions for titrations.
Never worked in a lab, but even our Chemistry courses eons ago had pipette bulbs as part of the lab equipment. IIRC, mouth pipetteing was explicitly forbidden. Maybe it was different in upper division synthesis classes or in grad school? My biochem labs had us using hand held autopipetters.
The only time I’ve seen anything similar to mouth pipetting in my years in undergrad labs, grad school, and as a professional scientist was in one fruit fly lab, where they used a mouth-powered suction system to move flies around on the pads. Most fly labs don’t have a system like that, though. As has been said, that’s an instant “you’re out of here forever” level of bad laboratorying.
Grin! The first mainframe computer I worked with had an led display of the CPU instruction register in binary, built into the front cabinet, just to provide blinking lights for those who utterly depend on such things. Many the long empty midnight hours I watched it flicker…
In Australia. And not in recent decades.
In high school we used (from memory), hand drawn pipettes with a rim pressed into the top end in order to catch the bulb, but that bulb was so awkward and inefficient that we resorted to mouth suction when the bulb slipped off or tore.
Nothing we used in that lab was really dangerous — although it was still ~10 years before the government went around and collected all the potentially interesting chemicals (stuff like sodium and benzoyl peroxide) from the back rooms of the old schools. But all our tutors and teachers remembered stuff like cleaning their teeth with HCL.