Comparison of antibody titers in 609 matched serum/EDTA-plasma specimens.
Serum and EDTA-plasma specimens were collected from the same donor at the same time during 2009 (Fig 1). Color codes indicate the fold difference in antibody titers between the matched serum/EDTA-plasma specimens: blue, orange and red indicate no, one-fold and two-fold or more difference, respectively. Pink shades indicate p<0.05 in Stuart-Maxwell test (i.e. statistically significant lack of marginal homogeneity between serum and EDTA-plasma titer distributions).