Beckman Coulter Inc. has released a chemiluminescent substrate to enable direct detection of hydrogen peroxide. Lumigen HyPerBlu combines a broad dynamic range and bright, sustained chemiluminescence for high-throughput-screening laboratory use. Reaction of the substrate with hydrogen peroxide rapidly generates sustained high-intensity luminescence for maximum sensitivity in solution assays. Direct detection increases accuracy and simplifies data analysis. When coupled with oxidases, the reagents also allow reliable, one-step, indirect detection of oxidases or their substrates. It is provided as a single solution and is stable for one year when stored in an amber bottle at 2 to 8 °C.