Area of Illumination (AOI)	The area illuminated by ultraviolet (UV) light to photo-release the photocleavable linker that are bound to targets for readout. It must be smaller than a field of view. There is a one-to-one correspondence between AOIs and collected “aspirates”, each to a single well in the AOI collection plate on the GeoMx DSP instrument. If a region of interest (ROI) does not fit into a single field of view, it is broken into multiple AOIs.
Digital Spatial Profiling (DSP)	DSP is intended to provide quantitative expression data in a spatial context. Through visual assessment of biological samples using microscopic imaging, researchers can specify ROIs to collect the quantitative expression information of RNA and protein targets.
Flow Cell	A general NGS term that refers to the sequencing surface and chamber.
GeoMx DSP System	The combination of the GeoMx DSP instruments, assays and software required to generate highly multiplexed DSP data.
Mask	Mask is binary ROI image metadata that encodes where the GeoMx must illuminate UV light within an ROI, thus resulting in the area of illumination (AOI).
Normalization	A data transformation that flattens differences in counts not arising by biology but by technical or sample variability (i.e., pipetting errors, difference in sample quality, etc.) between lanes, allowing the making of meaningful biological comparisons.
Readout (nCounter or NGS)	Digital counting of the hybridization target oligos in collected aspirates on either the nCounter or NGS system.
Region of Interest (ROI)	A region of interest as defined by the researcher. It may be arbitrarily large and have any shape the researcher considers appropriate. ROIs are specific to a given scan.
Resolution	The minimum UV illumination area that results in signal greater than background plus two times the standard deviation.
Scan	An image of a slide. Scans will have one or more imaging channels, may have additional metadata and may have annotated ROIs. A given slide can be scanned multiple times. Scans can originate in the GeoMx DSP system or can include imported images.
Segment	A uniquely defined sub-region of a given ROI. Segments may not overlap; the sum of all segments in an ROI does not need to be the entire ROI.