The Cas9/Crispr gene editing technology has the potential to revolutionize biology and medicine, due to its unique ability to generate site-specific DNA recombination and gene correction. However, the delivery of Cas9 still remains a problem, and this limits the scientific and medical applications of Cas9. Current methods for delivering Cas9 are primarily based on viral gene therapy, which is problematic due to toxicity from sustained expression and random genomic integration. Non-viral gene therapy has also been investigated for delivering Cas9, guide RNA and donor DNA into cells, however this is ineffective in numerous cell types, such as ES stem cells and primary cell lines, which represent the major applications for Cas9 gene editing. Researchers at UC Berkeley have developed a novel delivery vehicle, based on gold nanoparticles, termed CRISPR-Gold, which can be used to simultaneously deliver Cas9 protein, guide RNA and donor oligonucleotides into target cells and efficiently induce site directed DNA recombination. CRISPR-Gold is composed of nanometer sized gold nanoparticles conjugated with DNA, which have Cas9 protein, guide RNA, donor oligonucleotides and endosomal disruptive polymers complexed to them. Researchers have shown that CRISPR-Gold can deliver Cas9 protein, guide RNA and donor oligonucleotides into numerous cell types, including, stem cells, iPS cells and muscle progenitor cells, and induce gene editing and gene corrections with an efficiency that is significantly better than existing delivery vehicles. Additionally researchers have shown that CRISPR-Gold can perform gene editing in vivo and correct DNA mutations in mice via homologous recombination.