Sphingomyelinase Forster resonance energy transfer (FRET) probe is cleaved by recombinant human acid sphingomyelinase (rhASM) but not bacterial sphingomyelinase (bSMase). rhASM or bSMase were incubated in the presence of FRET probe and probe conversion was monitored by measurement of FITC fluorescence in a microplate reader. n = 3.
