Microarray analysis of pig innate immune responses after experimental infection with Actinobacillus pleuropneumoniae

To study hepatic gene expression differences, liver samples from infected pigs (n = 10) were compared with liver samples from the non-infected control group (n = 5). Ten microarrays were performed, such that 5 randomly selected cDNA samples from the infected group were labeled with Oyster 550 (Genisphere Inc., Hatfield, PA, USA) and compared directly to 5 control animals labeled with Oyster 650 (Genisphere) analysing a pair of samples (one from an infected animal and one from a randomly chosen non-infected animal) on each microarray slide. The remaining five cDNA preparations from the infected group were labeled with Oyster 650 and compared in the same way to the five controls labeled with Oyster 550 on the remaining 5 microarray slides. This dye-swap design was applied to reduce variation due to dye effects and to provide as much biological replication as possible. Keywords: Disease state analysis Two-condition experiment, Disease vs. Control, Biological replicates: 10 disease replicates and 5 control replicates, 10 Microarrays comparing one disease replicate with one control replicate.