Patent ID: 8313906

Claim:
A microfluidic device for purifying DNA from a sample comprising: (a) a sample port and lysis buffer port in fluid communication with a mixing region of the micro fluidic device, said mixing region being configured to permit mixing of a sample from the sample port and lysis buffer from the lysis buffer port mix; (b) a cell lysis region in fluid communication with the mixing region, said cell lysis region being configured to permit the lysis buffer to selectively lyse cellular membranes of cells in the sample without lysing nuclear membranes of the cells to produce intact nuclei from the cells in the sample; (c) a nuclei trapping region wherein intact nuclei from the sample are trapped by a filter via cross flow filtration while other components of the sample flow through the filter and into a waste collection region of the microfluidic device, said nuclei trapping region being in fluid communication with said cell lysis region; (d) a nuclei lysis region in which the nuclear membranes of the intact nuclei are lysed to release the DNA; (e) an elution buffer port in fluid communication with the nuclei trapping region and the nuclei lysing region, wherein elution buffer from the elution buffer port can be controlled to flow through the nuclei trapping region and the nuclei lysing region thereby lysing the nuclear membranes of the trapped intact nuclei to release the DNA; and (f) a DNA collection region in said microfluidic device wherein DNA released from the trapped intact nuclei is collected.