Feasibility of Multiplexing Bio-Plex Total Target and Phosphoprotein Assays

Bio-Plex assays allow detection of multiple target proteins in a small volume of sample. These assays report the level of a protein that is phosphorylated at a specific site or sites, while total target assays report the level of the protein regardless of its phosphorylation state. This note describes a study testing the feasibility of multiplexing a Bio-Plex total target assay with Bio-Plex phosphoprotein assays for different target proteins and was designed to answer two questions:

• Can a total target assay be multiplexed with phosphoprotein assays?
• Can a total target assay detect differences in protein concentration among samples?