Universal reference total RNA is control total RNA derived from whole-tissue sources. Each species-specific reference total RNA is made by pooling the total RNA extracts from a collection of different tissues, thus providing the broadest coverage of expressed genes. With each of reference total RNA sample, you can easily compare microarray or real-time PCR data generated from different experiments. For microarray experiments, simply hybridize a reference total RNA probe to a microarray each time you perform an experiment, and then use the control signal to normalize your results. We provide enough reference total RNA for up to 80 microarray experiments depending on the labeling technique. Since these RNA mixes are prepared on an industrial scale, there is minimal lot-to-lot variability. Our reference total RNA is the best approach for building gene expression databases to compare expression profiles from different tissues or cell lines.