Table 1 Comparison between the digital immunosensor assay (DigitISA) developed here and conventional surface-based immunosensor assays for protein detection
From: Direct digital sensing of protein biomarkers in solution
Digital immunosensor assay (DigitISA) | ELISA and bead-based immunoassays |
|---|---|
Free solution | Surface-based |
Complete binding of target molecules achievable even with low affinity probes | Capture efficiency determined by Kd and surface concentration of affinity probe |
Single-step assay with fast removal of excess affinity probe | Multi-step assay involving washing steps for removal of excess probes and reagents |
Specificity from combined affinity and electrophoretic criteria | Specificity from affinity criteria only |
Single affinity reagent | Affinity reagent pair |
Absolute number–concentration quantitation through digital detection | Generally reliant on calibration to convert signal to target concentration |
Multimodal readouts with information on immunochemistry/valency and stoichiometry, expression level etc. | Simple binding scenarios and limited information on binding modes |
Complex and transient systems such as oligomers and liquid condensates | Only targets that do not interfere with surface |
