A system for collecting target nucleic acids from a sample can include at least one sample chamber configured to receive a sample containing target nucleic acids and other material, at least one collection chamber removably mountable relative to the at least one sample chamber and configured to collect target nucleic acids separated from the other material, a filter removably mountable relative to the at least one sample chamber and configured to be disposed between the at least one sample chamber and the at least one collection chamber when the at least one collection chamber is mounted relative to the at least one sample chamber. The system may further include a pair of electrodes configured to generate an electric field sufficient to cause target nucleic acids in the at least one sample chamber to migrate via electrophoresis from the at least one sample chamber through the filter into the at least one collection chamber, wherein the filter may be configured to permit passage of target nucleic acids and to block passage of material of a size larger than the target nucleic acids.