Ligation-mediated PCR is a strategy of single-sided PCR based on ligation. First, a common linker is linked to one end of DNA fragments, then DNA sequence is amplified between the common linker and a sequence-specific primer. The application of vent DNA polymerase and strategies of extension products capture and linker tag selection greatly improves the sensitivity of ligation-mediated PCR. The invention of this technique has facilitated the execution of in vivo footprinting study.