Undead Attraction

Science isn’t just about pouring colourful liquids between test tubes. Sometimes your experiments are bizarre and fun — more often they’re tedious and require more focus than you knew you had. Below are the weirder technologies that researchers used to work out why bacteria make geosmin.

Frankenstein’s springtail sensing geosmin from beyond the grave. Photo by Matt Bush on Twitter.

How can you show that geosmin triggers a response in springtail brains?

1. It’s time for some precision surgery, and I mean precision: a springtail is 3 millimetres long and you’re about to remove its half millimetre head.
2. Fill a very thin glass capillary tube with Ringer’s solution — a liquid with a similar salt balance to a springtail’s body fluids.
3. Take the severed head and pop it into the tube, gore side first.
4. Hook up the other end of the capillary tube to an electrode — now you can measure the electrical signals that the zombie springtail brain produces.
5. Puff purified geosmin at the head — its antennae will sense the geosmin, and activate circuits in the brain, which you’ll see as spikes in the electrical signal measured.