Amersham Biosciences, now GE Healthcare, of Piscataway, NJ, has received US Patent No. 6,943,242, "Design of artificial genes for use as controls in gene expression analysis systems." The patent describes a method of producing controls for use in gene expression analysis systems such as macroarrays, real-time PCR, northern blots, SAGE, and microarrays. The controls are generated either from near-random sequence of DNA, or from inter- or intragenic regions of a genome. Ten specific control sequences are also disclosed in the patent.