A method of capturing a sperm deoxyribo nucleic acid (DNA) in a sample is disclosed. The method includes a step of contacting a lysis solution to the sample that includes at least a sperm cell or a sperm cell lysate to lyse the sperm cell. The sperm cell or sperm cell lysate includes a protamine-DNA complex. The method further includes applying at least a protamine-specific antibody to the lysed sperm cell, wherein the protamine-specific antibody binds to the protamine-DNA complex of the lysed sperm cell to form an antibody-protamine-DNA complex. The method further includes capturing the antibody-protamine-DNA complex; and isolating and detecting the sperm DNA from the captured antibody-protamine-DNA complex.