The SoPRano™ label-free assay is based upon Localized Surface Plasmon Resonance (LSPR) which can be found in substances such as Gold Nano Rods (GNRs). GNRs have a specific absorbance maximum (λmax) and when proteins are subsequently bound to the GNRs, this λmax shifts to the red region of the spectrum. This means that different proteins and different protein concentrations bound to the GNRs will have a different change in λmax. Therefore the λmax and the change in λmax must be determined for each new SoPRano™ assay. To help with the data analysis, Pharma Diagnostics has created a ratiometric method that accurately measures this change in λmax.
|Fig.2: Binding of hSA to its Antibody Using SoPRano™ LSPR. |
Increasing amounts of the hSA antibody were added to GNRs
pre-conjugated with hSA. A dose-response binding curve
is produced using the ratiometric data
To learn more about the SoPRano™ assay please see our application note or contact your local BMG LABTECH representative.