February 1, 2026
Shots fired: Espresso stains science
Coffee as a staining agent substitute in electron microscopy
Espresso replaces toxic lab stain — and the comments are frothing
TLDR: A TU Graz team found ordinary espresso can replace a toxic stain in electron microscopy, with equal or better image clarity. The comments brewed jokes, brand wars, and Ignobel talk, plus skepticism over “ordinary espresso” and reminders to skip hazelnut syrup—science just got caffeinated.
Scientists at TU Graz say ordinary espresso can stand in for a toxic, mildly radioactive lab stain used to make tissue slices visible under an electron microscope — and the internet immediately spilled its latte. The team at FELMI‑ZFE found coffee delivered equal or even better contrast than uranyl acetate, meaning the tiny cell details pop more clearly. They got the idea from those infamous dried coffee rings in mugs, and published the results in Methods.
Cue the community chaos. The strongest vibes? Pure comedy and brand‑war snark. One commenter crowed, “Finally, something Starbucks is good for!” while another meme’d, “One does not simply … ordinary espresso,” launching a mini‑debate over whether lab‑grade coffee means Italian roast only, decaf banished, and no hazelnut syrup allowed. Skeptics rolled their eyes at the coffee‑cup origin story (“Suuure…”), implying this was accidentally discovered in a caffeine-fueled lab clean‑up. Meanwhile, hype beasts called it Ignobel prize‑worthy, promising hat‑eating if it doesn’t get a nod.
Under the froth: a real question about practicality. Fans cheer a safer, greener swap; skeptics want to see more tissue types tested, per the researchers’ own caution. But for now, the mood is caffeinated delight: science just brewed a solution, and the comments are steaming with jokes, doubts, and dunking.
Key Points
- •TU Graz researchers found ordinary espresso can substitute for uranyl acetate as an electron microscopy stain.
- •Images from espresso-stained samples showed comparable or better contrast than uranyl acetate-treated samples.
- •Comparative tests used ultra-thin mitochondrial sections and image analysis software under identical conditions.
- •The idea originated from observing dried coffee cup stains; ultramicrotomy was used for sample preparation.
- •Further validation across diverse tissue types is needed before broad adoption in life sciences EM.