miRNAs are known to involve in multiple biological functions and abnormal expression is associated to human diseases such as cancers. They represent a promising new class of cancer biomarkers. A number of PCR methods have been developed for analyzing the expression level of miRNA. Based on its proprietary technology, Signosis has developed a highly sensitive and discriminative real-time PCR assay method for measuring miRNA expression. It implements oligo-ligation and SYBR green based real-time PCR. The assay can be used for quantitative analysis of miRNA expression in either total RNA or cell lysate without cDNA conversion.