Comparison of red-cell folate immunoassay results. A. Elecsys 2010 vs Advia Centaur. B. Unicel Dxl 800 vs Advia Centaur. C. Elecsys 2010 vs Unicel Dxl 800. The dotted lines are for equality, or zero error. The dashed lines are the 95% confidence interval, and the dot-dashed lines are the 99.9% confidence interval. The solid lines are the linear regression lines.