Cross-species hybridisation of pig RNA to human nylon microarrays

BMC Genomics

Table 3 Concordance within replicates of same- and cross-species hybridizations to a human nylon cDNA microarray

Type of RNA	Pearson^a	Spearman^b	Weighted Kappa^c
Human, 4 μg	0.97	0.97	0.86
Pig, 2 μg	0.97	0.97	0.82
Pig, 4 μg	0.97	0.97	0.80
Pig, 6 μg	0.96	0.97	0.86

^aPearson correlation coefficient assumes data are normally distributed. ^bSpearman correlation coefficient assumes data are symmetrical. ^cThe weighted Kappa statistic assumes data are ordinal. . Pearson and Spearman correlation coefficients were calculated from median normalized and log transformed data. All genes were categorized according to their normalized expression level (undetectable, 0; low, 0 to 1.3; medium 1.3 to 3.0; or high, >3.0) for calculation of the weighted Kappa statistic. Results are the average of the three pairwise comparisons among three hybridizations of each type of RNA.

ISSN: 1471-2164