Methods for capturing nucleic acids

A method of capturing a target nucleic acid on a capture zone of a substrate, comprising:

• applying a nucleic acid capture probe to a capture zone of a substrate, wherein the nucleic acid capture probe has a first molecular weight and comprises multiple copies of an identical region that is complementary to at least a portion of a sequence of the target nucleic acid such that the target nucleic acid hybridizes to multiple regions of the nucleic acid capture probe after the target nucleic acid interacts with the nucleic acid capture probe on the capture zone of the substrate, wherein the nucleic acid capture probe has a length in a range from about 20,000 bases to 150,000 bases, and wherein the nucleic acid capture probe is substantially immobilized at the capture zone of the substrate by entanglement of the nucleic acid capture probe with the substrate at the capture zone;
• thereafter applying a sample comprising the target nucleic acid to a sample application zone of the substrate, wherein the target nucleic acid has a second molecular weight;
• flowing a liquid across a length of the substrate from the sample application zone to the capture zone to migrate the target nucleic acid from the sample application zone to the capture zone by a lateral flow;
• and
• capturing the target nucleic acid using the nucleic acid capture probe by hybridization of the target nucleic acid to the nucleic acid capture probe on the capture zone of the substrate.