Unsupervised hierarchical clustering of lectin microarray fluorescence. (A) Lectin array heatmap of scaled quantile normalized healthy donor fluorescence. The normalized lectin microarray fluorescence data were scaled per row (lectin) to standardize the comparisons between samples. Red boxes represent higher fluorescence; blue boxes represent decreased fluorescence. Unsupervised hierarchical clustering of blood groups (top row) based on similar heat map patterns of lectin binding is shown. Individual lectins are indicated in the right column. (B) Principal component analysis of serologically identified blood group donors using lectin microarrays. The combination of all fluorescing lectins is reduced into a 2-dimensional format. The influence of a lectin is depicted by the length of the line and depth of color. The 9 statistically significant lectins are displayed. (C) Glycan structure cartoons depicting lectin binding preferences, indicated as gray boxed areas, are shown for each blood group. Selected lectins with known ABO specificity are indicated for group O (UEA-I, AOL, AAL, EEL, LCA), A (DBA, SBA, ACA), and B (EEL). Lectins previously unknown to have blood group specificity that influenced by ABO blood groups are also indicated (NPA and PWM), with these lectins recognizing mannose moieties.