Reference gene expression analysis within sample series 2: day 3, 5 and 21. (A) Intra-group variation (±CV). (B) Inter-group variation based on the average transcript quantities as illustrated in Figure 6A. (C) Differences in the average absolute quantities derived from sample series 1 and 2. All quantities are expressed as transcripts per 10 ng RNA. ±CV = (standard deviation/average) x 100%.