A method is disclosed for highly efficient DNA sequence alterations. The method is useful for editing chromosomes, to engineer cellular markers through insertion of genes, or to create epigenetic changes by usingcas9-enzyme fusions where the enzymes can be DNA epigenetic modifying enzymes or chromatin modifying enzymes, etc. The technology also differs from all previously known technologies in that the CRISPR/Cas system can function in ways that are “clean”,i.e. they have not been in contact with any virus, or are carried DNA molecules that can insert into the chromosome in unintended locations.本發明揭示一種用於高效DNA序列改變之方法。該方法適用於編輯染色體，經由基因插入來工程改造細胞標記物，或藉由使用cas9酶融合物產生表觀遺傳變化，其中酶可為DNA表觀遺傳修飾酶或染色質修飾酶等。該技術亦不同於所有先前已知之技術，不同點在於CRISPR/Cas系統可以「乾淨」之方式起作用，亦即其尚未與任何病毒接觸，或攜帶可在非預期位置插入染色體之DNA分子。
