Flexibility: Bead-based protocols are easily adapted for rapid processing of most available assays.
Cost-efficiency: Minimal reaction chamber volume implies >10-fold reduction in ELISA kit reagent consumption which, with chip regeneration convenience, results in most competitive data- point pricing.
Three types of immunoassays have been developed, i.e.:
A one-step method, in which coated micro-beads, sample and detection antibody are pre- incubated (in tube), and only thereafter introduced into the micro-channel.
A two-step method, in which a pre-incubated mix of coated micro-beads and sample is introduced first, and detection antibody afterwards (upon pre-concentration of beads within the micro-channels).
A three-step method, in which coated micro-beads, sample and secondary antibody are sequentially dispensed in the biosensor chip, without prior incubation step.