CRISPR/Cas gene editing system and preparation method and application thereof

The invention provides a CRISPR/Cas gene editing system and a preparation method and application thereof, and belongs to the technical field of gene editing. The CRISPR/Cas gene editing system includes pcDNA3.1-LjCas9 plasmids and pLjCas9-sgRNA plasmids. The application includes the following steps that a target sequence is determined, and single-stranded oligonucleotide pairs are designed; double-stranded DNA fragments are obtained through annealing; the double-stranded DNA fragments are connected with the insides of the pLjCas9-sgRNA plasmids to obtain a target-sequence sgRNA expression vector; cells are transfected with the target-sequence sgRNA expression vector and the pcDNA3.1-LjCas9 plasmids together and then cultured. The gene editing system can specifically cut target DNA, and theediting efficiency is high. 本发明提供了一种CRISPR/Cas基因编辑系统及其制备方法和应用，属于基因编辑技术领域，所述CRISPR/Cas基因编辑系统包括pcDNA3.1-LjCas9质粒和pLjCas9-sgRNA质粒。所述应用包括以下步骤：确定靶标序列，设计单链寡核苷酸对；退火获得双链DNA片段；连接到pLjCas9-sgRNA质粒中获得靶标序列sgRNA表达载体；靶标序列sgRNA表达载体与pcDNA3.1