Fig. 2.

Average relative intensity of each compound per cluster for the major, intermediate and minor N-glycans. Clusters A (Lab 8) and B (lab22) showed a complete difference with the other participating laboratories in term of repartition for PSA and PSA high isoform. Lab 8 reported Hex₄HexNac₃dHex₁Neu₁ as the major compound (> 60%) for the PSA sample, while clusters C and D reported the same compounds with an intensity lower than 15%. Lab 8 did not report any of the major N-glycans that the other labs observed for PSA High Isoform and PSA except the Neu₁dHex₁Hex₄HexNac₃. Cluster B for PSA and PSA high Isoform presented higher intensity for N-glycans Hex₅HexNac₃Neu₂ and Hex₅HexNac₄dHex₁Neu₂ than the other clusters C and D. Only in cluster C were intermediate N-glycans detected. In cluster A, the average relative intensity of compound dHex₁Hex₅HexNac₄ is 23.5% while it is lower than 6% for all the other clusters. (b) Minor N-glycans. The main difference is observed for the compound Hex₆HexNac₄NeuAc₁ of the PSA high isoform that is detected by cluster A with a relative intensity of 68% compared to less than 1% for the other clusters.