Practice question

Double digestion involves incubating DNA with two different restriction endonucleases either simultaneously in a compatible buffer or sequentially. The goal is to generate overlapping cleavage maps and assess relative positions of two distinct recognition sequences. Single enzyme digestion provides limited information. Exonuclease digestion degrades from termini rather than cutting internally at specific motifs. PCR-based methods are amplification techniques. Co-digestion with two enzymes typically yields smaller fragments and helps confirm insert orientation, construct verification, and detailed physical maps for cloning strategies.