Multi Nuclease all-around nuclease, also called broad-spectrum nucleic acid enzyme, is a kind of comes from Serratia Marcescens restriction endonuclease. It is capable of degradation of all forms of DNA and RNA （double-stranded, single-stranded, linear, circular or superhelical forms） under a very wide range of conditions （6Murea, 0.1M GuanidineHCl, 0.4%TritonX100, 0.1%SDS, 1mM EDTA, 1mM PMSF）. The formation of 3-5 oligonucleotide residues containing 5 '-phosphate terminus is widely used to remove nucleic acids from biological products. The expression and purification of this product in Escherichia coli（E.coli） through genetic engineering can not only reduce the viscosity of cell supernatant and cell lysate in scientific research, but also improve the efficiency of protein purification and functional research. It can also be used in virus purification, vaccine production, protein and polysaccharide pharmaceutical industry as a host residual nucleic acid removal reagent, reducing the host residual nucleic acid to the peak （pg） level to improve the efficacy and safety of biological products. And can effectively prevent human peripheral blood monocyte （PBMC） clumping in cell therapy and vaccine research.