The CRISPR-Cas9 gene editing system has been hailed as a promising solution to a range of genetic diseases, but the technology has proven difficult to deliver into cells. One strategy is to open the cell membrane using an electric shock, but that can accidentally kill the cell. Another is to use viruses as couriers. Problem is, viruses can cause off-target side effects. Scientists at Fred Hutchinson Cancer Research Center are proposing an alternative delivery vehicle: gold. They developed gold nanoparticles that can be packed with all the CRISPR components necessary to make clean gene edits. When they tested the gold nanoparticles in lab models of inherited blood disorders and HIV, between 10% and 20% of the targeted cells were successfully edited, with no toxic side effects.