Direct purification of CRISPR/Cas ribonucleoprotein from E. coli in a single step

Abstract

CRISPR/Cas ribonucleoprotein (RNP) complexes have been recently used as promising biological tools with plenty of applications, however, there are by far no efficient methods to prepare them at large scale and low cost. Here, we present a simple method to directly produce and purify Cas RNP, including the widely used Cas9 and Cas12a nuclease, from E.coli in a single step using an ultra-high-affinity CL7/Im7 purification system. The prepared Cas RNP shows high stability, solid nuclease activity in vitro, and profound genome editing efficiency in vivo. Our method is convenient, cost-effective, and applicable to prepare other CRISPR associated nucleases.