In the middle of the last century, a bacterial geneticist in Wisconsin developed a near obsessive interest in velvet. “Like many wives,” wrote a local paper with a jocular wink, Esther Lederberg ordered bolts of the thick-pile fabric, and was particular about the provenance of the product.
But unlike “many wives,” Dr. Lederberg had recently discovered a new experimental technique that would push the study of microbiology into new territory, ushering in an exceptionally productive period for molecular genetics.
Bent over clusters of E.coli cells in her University of Wisconsin lab, Dr. Lederberg discovered that the dense bristles of velvet could be used like tiny needles to capture and blot, in the same spatial orientation, a bacterial colony from one petri dish to another.
Soon she was hunting down yards of the lushest velvet on the market, determining which detergents best suited the textile and which manufacturers treated their product with chemicals that could lead to a confounding variable. Replica plating—a fundamental lab…