As shown most spectacularly by the fireworks-like rise and explosion of Theranos, there is an urgent need for diagnostics that can detect very low amounts of their targets in very small sample volumes. Amplification systems exist for nucleic acids, but not for proteins. Now, researchers from the Massachusetts Institute of Technology have developed a method, which they have termed hierarchical nanofluidic molecular enrichment system (HOLMES) – named, one hopes, for Sherlock, not Elizabeth – for amplification of very low concentrations of solutes from fluids, including blood serum and urine.