Simoa stands for Single Molecule Array. It is is an ultrasensitive immunoassay technology that allows for detection of biomarkers, such as proteins, at very low levels. With Simoa, one can achieve sensitivity that is orders of magnitude higher than standard sandwich-based immunoassay techniques, detecting as little as femtogram (fg/mL) concentrations, while consuming as little as 1 µL of sample. As such, this ultrasensitive detection capability allows for the quantification of biomarkers at concentrations that have previously been difficult or impossible to measure.