Recent research has been focused on methods for the large-scale re-engineering of bacterial genomes. Scientists at the J Craig Venter Institute are developing the means for synthesizing genomes from scratch and inserting these genomes into bacteria whose DNA has been removed in order to create "synthetic life." (see Gibson et al. 2010. Creation of a Bacterial Cell Controlled by a Chemically Synthesized Genome. Science 329:52. doi:10.1126/science.1190719). George Church and colleagues have developed an alternative approach that involves making small sets of mutations in a different number of bacterial strains, then stitching together these mutations into a single re-engineered bacterial genome (see Isaacs et al. 2011 Precise Manipulation of Chromosomes in Vivo Enables Genome-Wide Codon Replacement. Science 333:348. doi:10.1126/science.1205822 ).