Chemical additive screening in microplates
Chemical additives for screening were diluted in either sterile water or dimethyl sulfoxide (DMSO, 100% v/v) where appropriate. Low, medium and high concentrations for each chemical were based on available literature describing their observed effects on recombinant protein expressionin vitro (listed in Table S1). Cells were initially grown to a density of 4 x 106 viable cells/mL in Erlenmeyer flasks and mid-exponential phase cells were transfected with AAV-encoding plasmids prior to transferring to 24-shallow-well microplates (Corning) at 2.8x106 cells per well, 20 min post-transfection. Chemical additives were added to cells 24 hours post-transfection (HPT). Cell cultures were harvested at 72 HPT for viral genome titre analysis by ddPCR.