Sandwich ELISA Application Guide

How sandwich ELISA works

A capture antibody immobilises the analyte and a second detection antibody recognises another accessible epitope. The resulting signal is compared with standards prepared across the validated assay range.

1. Use a compatible matched-antibody pair and the specified plate format.
2. Prepare standards, controls and samples according to the assay protocol.
3. Capture the analyte and add the detection system.
4. Develop the signal, fit the standard curve and review replicate precision.

Experimental planning and controls

Sample matrix, dilution, recovery, parallelism, replicate precision and the validated assay range can all affect interpretation. Avoid unsupported extrapolation outside the standard range. For commercial kits, the manufacturer manual is authoritative for volumes, incubation times and calculation rules.