normalized to large acidic ribosomal protein (RPLPO) [33 (link)]. Immunoreactivity to target proteins was
detected with horseradish peroxidase-conjugated secondary antibody and Amplex
UltraRed soluble fluorophore (Invitrogen, Carlsbad, CA). RPLPO antibody
(Proteintech Group Inc, Chicago, IL) was biotinylated, and its immunoreactivity
was detected with streptavidin-conjugated alkaline phosphatase and the
4-Methylumbelliferyl phosphate (4-MUP) substrate. Fluorescence intensities
(Amplex Red: Ex 565 nm/Em 595 nm; 4-MUP: Ex360/Em450) was measured in a
SpectraMax M5 (Molecular Devices, Sunnyvale, CA). Antibody omission controls
were included. The calculated target protein/RPLPO ratios were used for
inter-group comparisons.