The NanoString nCounter gene expression system uses multiplexed probe hybridization to capture and count individual mRNA transcripts. Transcripts for each gene are targeted by a pair of gene-specific probes - a biotinylated capture probe to capture the transcript on a streptavidin-coated slide, and a reporter probe containing a color-coded pattern of fluorescent segments. Imaging of the slide can then identify each captured transcript. [ http://www.ncbi.nlm.nih.gov/pubmed/18278033 http://orcid.org/0000-0002-2443-7325 ]