In BE proteins with gRNA. Delivery of RNPs

In an important recent study, It was argued that DNA
delivery method using plasmid vectors results in uncontrolled Cas9 and sgRNA expression even after
the on-target locus has been edited, thus providing opportunity for off-target
editing. Therefore, delivery of exogenous DNA plasmid
vectors was replaced by DNA-free lipid mediated delivery of ribonucleoproteins
(RNPs) prepared through association of BE proteins with gRNA. Delivery of RNPs when
tried in mice inner ear and zebrafish embryos exhibited much higher target
specificity and reduced off-target editing21.