Number of words: 185

In 1965, at Michigan State University, a biophysicist, Barnett Rosenberg, began to investigate whether electrical currents might stimulate bacterial cell division. Rosenberg devised a bacterial flask through which an electrical current could be run using two platinum electrodes. When Rosenberg turned the electricity on, he found, astonishingly, that the bacterial cells stopped dividing entirely. Rosenberg initially proposed that the electrical current was the active agent in inhibiting cell division. But the electricity, he soon determined, was merely a bystander. The platinum electrode had reacted with the salt in the bacterial solution to generate a new growth-arresting molecule that had diffused throughout the liquid. That chemical was cisplatin. Like all cells, bacteria need to replicate DNA in order to divide. Cisplatin had chemically attacked DNA with its reactive molecular arms, cross-linking and damaging the molecule irreparably, forcing cells to arrest their division.

Excerpted from page 204 of ‘The Emperor of All Maladies: A biography of Cancer’ by Siddharth Mukherjee