Verification of array data by RT-PCR. Array data were confirmed for a subset of genes by semi-quantitative RT-PCR. Total RNA was isolated from untreated and 5-AzaC treated parasites (7 days) and subjected to RT-PCR. Sequential 1:10 dilutions of cDNA were used as template for the PCR and a genomic DNA and minus RT control (-RT) were included. The microarray expression fold-change for each gene is shown based on average array data from 3 day and 7 day 5-AzaC treated parasites. Two genes (115.m00143 and 141.m00082) that were predicted to be upregulated (based on array data) after 5-AzaC exposure were confirmed by RT-PCR. Two genes (2.m00545 and 226.m00092) that were predicted to be down-regulated (based on array data) after 5-AzaC exposure were confirmed by RT-PCR. A gene whose expression did not change (based on array data) with 5-AzaC exposure (147.m00095) was found to be unchanged in the two conditions by RT-PCR. Primers used are given in Table 1.