The paper discusses the reasons for the resurrection of the term DNA microcircles through the change of its definition to "topologically closed DNA circles with the length less than 1 Kbp" from the entire population of circular DNA that holds the name of minicircles. The possible applications of such tool for in vivo studies of non-canonical DNA are also discussed. Prospective for in vivo and in vitro studies of non-canonical DNA cloned into microcircles are demonstrated. A method of stepwise elongation or shortening of plasmids is discussed.