AllStars Negative Control siRNA is the most thoroughly tested and validated negative control siRNA currently available. This siRNA has no homology to any known mammalian gene. Validation has been performed using Affymetrix GeneChip arrays and a variety of cell-based assays to ensure minimal nonspecific effects on gene expression and phenotype. Minimal nonspecific effects ensure that comparison of the gene-specific siRNA to the negative control gives a true picture of the effects of target-gene knockdown on gene expression and phenotype. If the negative control causes nonspecific effects then results from RNAi experiments can be misleading and difficult to interpret. Cloning experiments confirmed that AllStars Negative Control siRNA enters RISC. AllStars Negative Control siRNA is patent-pending and the sequence is proprietary.