Total RNAs were purified from neurons derived from the parental apoE4/4-hiPSC and the isogenic apoE3/3-hiPSC lines using Qiagen Rneasy mini kit. cDNAs were reverse transcribed from total RNA using oligo dT as primers (SuperScript™ III First-Strand Synthesis System, ThermoFisher Scientific). Using the resultant cDNAs as templates, the coding sequence of APP, MAPT (Tau), BACE1, and PS1 were amplified with corresponding 2–3 pairs of PCR primers. The coding sequence of the NPLOC4 gene was also amplified because it was predicted as a potential off-target gene of the gene editing approach using the program Prognos. All PCR products were then purified and sequenced. The sequencing data were then used to blast search database for DNA sequence alignment.
