Validation of the microarray by alternative expression assays. A. qRT-PCR analysis of the expression profile of six test transcripts identified as being enriched in stumpy forms by microarray hybridization. The relative expression is shown (y-axis) at each time point (x-axis), the expression ratio being normalised to a control transcript (Tb10.389.0540). B. Northern blot showing the relative expression of trypanosome alternative oxidase (Tb10.6k15.3640) in samples from one time course assay, using the same mRNAs used for microarray hybridization. The relative loading is indicated by the rRNA beneath the blot, this being revealed by ethidium bromide staining.