Proliferation Assay
CCO cells were seeded at 0.8x104 cells per well on a
black 96 well plate with optical bottom (Thermo Scientific) in L-15 with
1% FBS 100μl. Following adherence, cells were treated with varying
concentrations of cfIL-22 or pBK empty vector control (negative) for 24
hours. Resazurin sodium salt (0.15mg/mL; Sigma) was dissolved into DPBS
(pH 7.4, Corning, Fisher Scientific), sterilized through a 0.2µm filter
and stored at 4°C for up to two weeks in a light protected container.
Resazurin (20 μl) was added to each well and incubated for 3 hours at
28°C. Fluorescence was read using a Biotek Synergy 2 plate reader
(Excitation 560nm/emission 590nm). Data are analyzed in Microsoft Excel
and reported as relative fluorescent units.