The present invention discloses a filter membrane and a method for extracting
DNA from physical evidence samples, comprising the following steps: S1: soaking the filter membrane with a first
magnetic bead suspension, filtering the first
magnetic bead suspension soaked with the filter membrane until the liquid on the filter membrane is drained, thereby obtaining a filter membrane adsorbed with magnetic beads; S2: flushing the surface of the physical evidence sample with a mixture of a
buffer solution and a second
magnetic bead suspension to obtain an enriched liquid, filtering the enriched liquid with the filter membrane adsorbed with magnetic beads until the enriched liquid on the filter membrane is drained, thereby obtaining a filter membrane enriched with
DNA and / or
body cells; S3: extracting
DNA from the filter membrane enriched with DNA and / or
body cells. The present invention solves the problem that existing
extraction methods cannot accurately extract DNA from physical evidence samples that are large in size, have good
water resistance, are irregular in shape, have few detached cells, and are scattered, thereby achieving the purpose of accurately extracting trace DNA from multi-type, multi-morphological, and irregular physical evidence samples.