In November 200 1, Nature published a letter in which University of California Berkeley’s biologists claimed to have found evidence of genetically modified (GM) DNA in regional varieties of maize in Oaxaca, even though the Mexican government had banned transgenic corn agriculture in 1998. While urban protesters marched against the genetic ‘contamination’ of Mexican corn by US-based agricultural biotech firms, rural indigenous communities needed a framework for understanding concepts such as GM before they could take action. This article analyzes how the indigenous organization, the Zapatistas, mobilized a program to address this novel entity. Their anti-GM project entailed educating local farmers about genetics, importing genetic testing kits, seed-banking landrace corn and sending seeds to ‘solidarity growers’ around the world. This article explores material-semiotic translations to explain one of the central aspects of this project, the definition and circulation of Zapatista corn–an entity defined not only through cultural geography, but also technological means. Through its circulation, Zapatista corn serves to perform a biocultural engagement with Zapatista’s political project of resistance to neoliberalism. While much has been written about both regulatory policy and consumer activism against GM in the Global North, Zapatista corn also provides a case study in indigenous, anti-GM activism founded on biocultural innovation and the creation of alternative networks for circulating corn.