The present invention concerns a novel method and assembly for extraction of regenerative cellular components from an adipose tissue, the method comprising the steps of filtering a harvested adipose tissue for recovering its liquid fraction by means of a filtering element having a first cut-off value comprised between 40 microns and 70 microns; separating regenerative cellular components present in the liquid fraction by means of cell size segregation which blocks cells bigger than a second cut-off value ranging from 8 to 20 microns; and recovering the regenerative cells-rich fraction comprising the regenerative cellular components not having being blocked during the separating step.