Figure 2
Quality index heatmap plot for SNP arrays of different quality and pooled DNA. This figure shows quality index Q2 for Nsp arrays, Sty arrays, and merged Nsp and Sty arrays for 16 DNA samples. The first four samples and the second four samples were genotyped using unexpired arrays. The third four samples were genotyped with expired arrays. The last four samples were DNA pools constructed by 56, 198, 52 and 192 individuals and genotyped using unexpired arrays, respectively. The magnitude of the quality index is presented using a heatmap plot for which a color spectrum from dark green to white represents the magnitude range. The levels of the quality index (μ, μ + σ, μ + 2σ, μ + 3σ, μ + 4σ, μ + 5σ and μ + 6σ) are given, where μ and σ denote the sample mean and standard deviation, respectively, of the quality index for the normal reference samples. Moreover, the upper limits of the quality index for arrays Nsp (N), Sty (S), and Merge (M) are also given in the key. For the 16 DNA samples, if the values of the quality indices of arrays Nsp, Sty and Merge are greater than these upper limits, arrays are presented in light-blue shaded views, respectively.