Biotinylated cRNA samples prepared from Arabidopsis leaves at 3 d after BTH treatment (B3D) were used for this experiment. The cRNA was hybridized to either microspheres (coupled with single-probe, 1P; three-probe, 3P; and six-probe, 6P; respectively) made by Luminex or Arabidopsis GeneChip made Affymetrix in separate experiments. The hybridization signals of the genes obtained from the two technologies were normalized to the expression level of UBQ4 as shown in A. The fold change in hybridization signal of the BTH-treated sample to the control sample is presented in B.