In mass spectrometry, data-independent acquisition (DIA) is a method of molecular structure determination in which all ions within a selected m/z range are fragmented and analyzed in a second stage of tandem mass spectrometry.[1][2] Tandem mass spectra are acquired either by fragmenting all ions that enter the mass spectrometer at a given time (called broadband DIA) or by sequentially isolating and fragmenting ranges of m/z.[3] DIA is an alternative to data-dependent acquisition (DDA) where a fixed number of precursor ions are selected and analyzed by tandem mass spectrometry.