Abstract: The invention is in the area of selective extraction of DNA from groups of cells. Selective lysis of a particular cell type within a cellular mixture is performed and then the mixture is separated with a filter that allows the DNA from the lysed cells to flow through the filter, while not allowing the unlysed cells to pass through, thereby selectively extracting the DNA from a particular cell type. In one specific embodiment, spermatozoa DNA can be isolated from biological samples which also contain epithelial cells. Methods and kits are also provided which allow for the sequential extraction of DNA from mixtures of cells. The DNA in the sample can be from human, animal or vegetal origin, or any combination of human, animal or vegetal DNA.