In a bid to accelerate its nanopore gene-sequencing technology, Roche has purchased Stratos Genomics for an undisclosed sum. Seattle-based Stratos brings its “sequencing by expansion” chemistry, which inserts large reporter molecules between the bases on a DNA strand. Different reporters bind to the four different DNA bases. Stratos says its platform increases the signal-to-noise ratio of nanopore sequencing, one of multiple competing next-generation gene-sequencing methods. The technology could have applications in personalized medicine and rapid response to future pathogens.