Figure S2 Testing epitope specificity using CTB and AS blockers in ELISA assays. GM1-specific sera standard was used as a sample in Buhlmann GM1 ELISA, and no blocking with either CTB or AS was observed (a). Effective blocking of GM1 by CTB was demonstrated in the in-house fluorescent ELISA, but no blocking effects of both CTB and AS were observed on the other gangliosides (b). Similar experiments using ganglioside Luminex bead array showed effective blocking of gangliosides with CTB and AS (Figure 2 in the main part). (TIF) Figure S3 Concentration sensitivity to ganglioside-spe- cific sera of BioPlex bead array, compared to Buhlmann ELISA. GM1-specific sera standard from Buhlmann kit was used References 1. Rees JH, Gregson NA, Hughes RA (1995) Anti-ganglioside GM1 antibodies in guillain-barre´ syndrome and their relationship to Campylobacter jejuni infection. Ann Neurol 38:809–816. 2. van den Berg LH, Marrink J, de Jager AE, de Jong HJ, van Imhoff GW, et al. 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