Despite the loss of cells from the tip of the villi, the amount of RNA (Table 1 ) isolated from all infected piglets was comparable to that of uninfected piglets. On an ethidium-bromide-stained agarose gel, no degradation of RNA was visible for any of the extracted RNA samples (see also Fig. 2a ). In addition, 28S/18S peak ratios were [2 for all these samples (Table 1 ). These results showed that scrapings collected from all piglets yielded high-quality RNA suitable for real-time PCR and microarray analysis. No random (necrotic) and/or fragmentized (apoptotic) DNA was visible after gel electrophoreses of DNA samples extracted from any of the piglets, indicating that the majority of cells imbedded in the epithelial layers of all the piglets were not apoptotic or necrotic (results not shown).