AccuBase™ (BS-EP1, Product name: AccuBase™) is a genetically engineered DNA cytosine base editor that efficiently modifies DNA within a range of 3-12 positions (with position No. 1 being farthest from the PAM site). By integrating the deaminase into the Cas enzyme, AccuBase™ minimizes random binding to non-target DNA, reducing off-target effects. AccuBase™, when combined with sgRNA (compatible with spCas9 sgRNA), forms an RNP complex. When the complex is transfected into cells and bound to the target site, it deaminates cytosine, creating uracil without causing DNA double-strand breaks. The cell's repair mechanism then changes the mutated site to thymine (T). This C->T mutation can knock out the target gene by generating a stop codon or mutating the alternative splicing site.