Ultra-sensitive multiplexed assay that limits noise from non-specific binding
An ultrasensitive assay that combines microarray and digital assay technologies was developed at McGill University.
Ultrasensitive assays are important for detecting small quantities during early diagnosis of diseases. An assay’s sensitivity is often limited by non-specific binding (NSB), though, which causes background noise. NSB causes fluctuations in the background signal and compromises the baseline with target molecules binding to the background surface and over saturation of non-target molecules. Two promising technologies for early detection assays are microarray and digital assays, but each have their limitations. Antibody microarrays are high antibody density, but their sensitivity is inadequate for early detection. Digital assays can reach single molecule resolution but are not scalable for large-scale protein analysis because of their lower antibody multiplexing capabilities. Unfortunately, non-specific binding is not sufficiently addressed in either technology.
This technology is a molecular detection assay that addresses sensitivity, antibody density, and noise rejection in a single platform. This unique assay was produced by four innovations. The first was a noise rejection method of reducing sample driven and reagent driven non-specific binding with a spatial discrimination technique. Using the noise rejection mechanism, a nanodot microarray printing technique was developed that is 1000 times more sensitive than traditional fluorescence microarray. The third innovation combines nanoarray noise rejection with the high density of different antibodies found in microarrays to allow better multiplexing for scale up processes. Finally, a customized image analysis algorithm for signal extraction of both single plex and multiplex assays was developed for an easier user interface.
- Spatially discriminates non-specific binding to improve background noise rejection
- Improves sensitivity by 1000-fold
- Scalability with multiplexing for large-scale protein analysis
- Customized image analysis algorithm for signal extraction of assays