Temperate bacteriophages (prophages) have recently been demonstrated in Campylobacter jejuni. However, what they do there is largely unknown. In the series of studies that are the subject of these submissions we have investigated the relative expression levels of proteins in C. jejuni isolates that differ in the presence or absence of the CJIE1 prophage. At the time of the initial investigations whole genome sequence data were not available for the isolates used, though DNA microarray data indicated that the isolates were very closely related. The overall project was carried out through four separate experiments. Previous work in the scientific literature indicated that growth on medium lacking blood but containing sodium deoxycholate induced the expression of at least some proteins associated with virulence and provided data thought to be of relevance to the virulence of the bacterium. The second set of experiments (experiment 2) therefore compared protein expression in 4-plex iTRAQ experiments using two isolates. Isolate 00-2425 carried the CJIE1 prophage while the second isolate, 00-2426, did not. Three replicate experiments were done. Each isolate was grown on Mueller Hinton agar base and Mueller Hinton agar containing 0.1% sodium deoxycholate.