Measurement of collagen-specific IgG titers
At 49 days post first CII immunization, serum was collected, then diluted at a ratio of 1:3,000 in blocking solution containing 1% bovine serum albumin in PBS. Collagen-specific total IgG titers were measured by coated 10 mg/mL of CII in PBS on 96-well plates. The optical density was read at 450 nm using a microplate reader.