We describe a technology, the NanoString nCounter
gene expression system, which captures and counts individual
mRNA transcripts. Advantages over existing platforms include direct measurement of
mRNA expression levels without
enzymatic reactions or bias, sensitivity coupled with high multiplex capability, and digital readout. Experiments performed on 509 human genes yielded a replicate
correlation coefficient of 0.999, a detection limit between 0.1 fM and 0.5 fM, and a linear dynamic range of over 500-fold. Comparison of the NanoString nCounter
gene expression system with
microarrays and TaqMan
PCR demonstrated that the nCounter system is more sensitive than
microarrays and similar in sensitivity to
real-time PCR. Finally, a comparison of transcript levels for 21 genes across seven samples measured by the nCounter system and
SYBR Green real-time PCR demonstrated similar patterns of
gene expression at all transcript levels.
