0.1 mM CSPD/10% chemiluminescence enhancer

100 μl of 25 mM CSPD (Tropix)

2.5 ml of chemiluminescence enhancer (Nitro-Block, Applied Biosystems)

22.4 ml of CSPD assay buffer

Filter the solution through a 0.2 μm filter, and store at 4°C. The chemiluminescence enhancer increases light output more than tenfold, which is critical for detection of very small amounts of protein.