The invention relates to an integrated system for microfluidic analysis of a liquid sample comprising a liquid sample preparing means (100) which is provided with a displacement means (101) for introducing the sample and reagents and for transmitting said sample and reagents to a second means (200) for chemically or biochemically treating the liquid sample drops, wherein said treating means comprises also means (201) for displacing sample drops to means (300) for drop analysis. Said invention is particularly suitable for a laser radiation desorption device comprising a system for manipulating the sample and reagents in the form of drops, which is provided with one or several loading posts, one or several transport paths consisting of interdigitated electrodes, one or several chemical or biochemical treatment areas and at least one system for switching to a conductive post on which a laser radiation desorption can be carried out.