Briefly, human embryonic kidney (HEK293T) cells were triple-transfected with pUCmini-iCAP-AAV-PHP.S, pHelper Plasmid, and one of the following pAAV genomes (CAG-NLS-GFP, hSYN1-tDTomato, GFAP-tDTomato, hSYN1-mRuby2, hSYN1-DiO-mRuby2, hSYN1-mNeonGreen, hSYN1-DiO-mNeonGreen, hSYN1-mTurquoise2, hSYN1-DiO-mTurquoise2, hSYN1-DiO-hM3Dq-mRuby2, CAG-GCaMP6F) in a DPBS + polyethylenimine (PEI)