Hyperactive pA-MNase for CUT&RUN fuses Protein A and Micrococcal nuclease (MNase) to form a novel fusion enzyme with their dual activities, and it is specifically for the CUT&RUN technology in protein-genome interaction research. CUT&RUN technology greatly simplifies the operation process of traditional ChIP-seq, only taking 1 - 1.5 days to construct the next- generation sequencing library from cells. Moreover, it has low cell input, high signal-to-noise ratio, good reproducibility, and is widely applied to research including early embryonic development, stem cells, tumors, and epigenetics.