supernatant

The phage-free supernatant served as a comparative control.

After removal of the supernatant, the pellet was washed using 100 µl 70% ethanol and dried in vacuum.

Then, the supernatant was transferred to a clean 1.5-ml Eppendorf tube and mixed with 250 µl isopropanol by gentle turnover several times.

Tubes were put on the magnet until the supernatant ran clear so that it could be removed and discarded.

Prior to microinjection, the ribonucleoprotein complex was prepared by centrifuging the Cas9 protein for 1 min at 14,000 r.p.m. at 4 °C and transferring the supernatant to a fresh tube containing the sgRNA.