Patent ID: 8304185

Claim:
A microfluidic system for isolating DNA from cells in a patient sample comprising: (a) a cell lysis region in which cellular membranes of the cells in the patient sample are selectively lysed without lysing the nuclear membranes of the cells to produce intact nuclei from the cells; (b) a nuclei separation region in a microfluidic device, said nuclei separation region comprising a nuclei size exclusion barrier which blocks passage of intact nuclei and which allows passage of other components of the patient sample to a waste reservoir, thereby permitting the isolation of intact nuclei by the nuclei size exclusion barrier; (c) an elution buffer port in fluid communication with the nuclei separation region for providing elution buffer to the nuclei separation region, wherein the elution buffer being driven by a pressure differential resuspends the isolated intact nuclei and carries isolated intact nuclei out of the nuclei separation region; (d) a nuclei lysis region in which the nuclear membranes of the intact nuclei are lysed to release the DNA, said nuclei lysis region being in fluid communication with the nuclei separation region; and (e) a control system which controls the flow of the patient sample through the nuclei separation region and controls the flow of the elution buffer through the nuclei separation region, wherein the control system causes the patient sample to flow in a first direction and causes the elution buffer to flow in a second direction, wherein said first direction is substantially orthogonal to said second direction.