Problem with Sandwich ELISA
Multiplexed sandwich immunoassay is a powerful technique to measure multiple protein concentrations simultaneously. Its wide adoption is hampered by inadequate antibody specificity which results in cross-reactivity and false positive signals This is a known weakness of multiplexed assays that is mitigated by months of assay optimization and validation, and despite considerable effort, it’s often impossible to combine related analytes in the same assay.
Parallex BioAssays Inc. substituted the “detection soup” by an array of detection nanodroplets and offers a new microarray-to-microarray approach to deliver the detection antibodies precisely to their cognate spots. As a result, a cross-reaction free chip harboring an assembly of parallelized assays, physically isolated from each other.
The SnapChipTMwas used to measure key proteins and PTM in the Akt pathway. The colocalization of the capture and detection antibodies allows to mix-and-match any existing singleplex. Indeed, the analysis of the 3 Akt isoforms in the same assay is not possible with other multiplex technologies because of cross-reactions and a lack of specificity of the antibodies. On the SnapChipTM, the assays are contained in nanodroplets and are physically isolated, which opens new opportunities and eliminates the risk of false positives. Other multiplex assays are available, and customized chips can be rapidly developed.
See below for a short video illustrating how the SnapChip technology is used. It shows how the two microarrays are overlapped using the SnapChip device.