Enlarge ImageSliced. A zebrafish larvae tail 3 minutes, 17 minutes, and 61 minutes (top to bottom) after being cut. Hydrogen peroxide (red) emanates from the wound, fading to yellow and green as it dissipates through tissue.Credit: Philipp Niethammer Anyone who has felt the sting as hydrogen peroxide foams and fizzes on a scraped knee knows about the compound's antiseptic properties. But new research suggests that hydrogen peroxide does more than just kill microbes. It may also call for reinforcements, summoning an army of bacteria-fighting cells to cuts and wounds. Punctured skin sets off a chain reaction of chemical signals...