A scorpion toxin makes brain tumors glow for surgeons

Researchers at the Fred Hutchinson Cancer Research Center in Seattle took a peptide from the venom of the deathstalker scorpion, which binds cancer cells far more than healthy tissue, and attached it to a fluorescent dye to see whether it could mark tumor tissue in real time.

In mice, the chlorotoxin compound lit up brain tumors under near-infrared light while leaving the surrounding healthy brain dark, and it outlined prostate, intestinal and sarcoma tumors the same way. In lymph channels it picked out spreading cancer clusters as small as a few hundred cells.

The compound, nicknamed tumor paint, later moved into early human trials testing whether surgeons can see tumor edges during an operation. It is not yet a standard tool in operating rooms, and larger trials are still needed to show it changes outcomes for patients.

A scorpion's venom, repurposed to draw the line.