The Finnigan LCQ DUO is a powerful, compact and affordable benchtop mass spectrometer for LC/MS/MS. The Finnigan LCQDUO lets you append or search library spectra against commercial and customized libraries, producing a powerful knowledge base of MS/MS spectra. The Finnigan LCQ DUO equipped with Xcalibur software permits in-line acquisition and integration of photodiode array (PDA) data along with mass spectral data. WideBand Activation a standard feature on the Finnigan LCQDUO, applies resonance excitation energy that fragments the molecular ion and any product ion up to 20 u less than the precursor ion. This is important because hydroxylated compounds frequently only show the loss of a water molecule in an MS/MS spectrum giving little structural information. Wideband Activation provides spectra with greater structural information and is invaluable for MS/MS library building, high-throughput screening and quantitation experiments.