Abstract: The present invention describes novel fluorescent compounds analogous to alkyl phospholipids, containing highly photostable fluorescent groups in the structure thereof and emitting in the visible spectrum wavelength zone. Said compounds are easily introduced to microorganisms, enabling the detection and identification of these organisms by means of fluorescence microscopy. The novel fluorescent compounds can also diagnose, rapidly and easily, the presence of pathogenic microorganisms characterised in that they are resistant to treatment with alkyl phospholipids.