Figure 1
Global comparison of PCR and T7 amplification techniques. (A) Microarray experimental design. S1 and S2, and M1 and M2 are technical repeats of PCR (S) and T7 amplification (M) respectively. Each arrow represents one slide where the sample at the base of the arrow is labeled with Cy™3 and the sample at the tip of the arrow is labeled with Cy™5. (B-D) Correlation of results within and between amplification techniques; the values are least square means of expression of each of the genes represented on the array. (B) The correlation between two technical repeats of gene expression after S amplification. (C) The correlation between two technical repeats of gene expression after M amplification. (D) The correlation between gene expression after S and M amplification. Each amplification method produces highly consistent results (R2 = 0.98) whereas the correlation of the results given by the two different methods is considerably lower (R2 = 0.52) indicating bias in one or both amplification techniques.