The Olink Proximity Extension Assay (PEA) uses four internal controls that are added into all 96 wells of the sample plate. These controls are used for quality control and for data normalization. The controls monitor all the different steps of the PEA, the controls and how they are used is outlined below:
The incubation controls consist of two non-human antigens (phycoerythrin (PE) and green fluorescent protein (GFP)) with matching antibodies/assays. Both of them are used for data quality control of the data and can be used to monitor all steps of the PEA.
This control is made up by IgG antibodies conjugated with a matching oligo pair, so that the DNA tags are always in proximity. The extension control is used for data normalization as well as for monitoring the extension reaction as well as the amplification and detection-steps.
The Detection control is a piece of synthetic double-stranded DNA that is used in the data quality control. This control can also help evaluate potential issues in the final amplification and detection steps.