In this review some aspects of the interactions of organized structures of amphiphiles with natural or synthetic DNAs are briefly considered. In particular DNAs encapsulated in closed cavities of amphiphiles, specifically giant vesicles and water-in-oil droplets and reverse micelles, are dealt with. Two main applications of giant vesicles are reviewed in detail, namely their use as microreactors where reactions can be followed by optical microscopy on a single vesicle and in synthetic biology as protocell models or as potential semi-synthetic “living” cells. Water-in-oil droplets uses for rapid and relatively low-cost DNA amplification by PCR reaction are described as well as for in vitro transcription and translation. A large variety of non-Watson–Crick conformations of polynucleotides observed in the aqueous inner core of reverse micelles is illustrated and compared with those observed in matched water solutions.