|dc.description.abstract||Human plasma is the most used specimen for diagnosis where the level and/or modification of some specific proteins are associated with the progression of disease. Because of the complex nature of disease, diagnosis using single protein assay often results in insufficient detection specificity. The development and application of a multiplexed assay provide advantages of reduced analytical time, lower cost of reagents and smaller sampling quantity. Unfortunately, the high protein content of plasma is present across an extraordinary dynamic range of concentration that is likely to span more than 1012, which result in analytical challenge.
Recent success of mass spectrometry in clinic proteomics has shown the ability to screen and discover multiple biomarkers simultaneously that increases the sensitivity and specificity of disease diagnosis. We have developed a multiplexed immunoassay based on nanoprobe-based affinity mass spectrometry (NBAMS) to specifically isolate, preconcentrate, and characterize several disease-associated antigens in plasma simultaneously. To demonstrate the availability of the approach, three serum proteins, C-reactive protein (CRP), serum amyloid P component (SAP), and serum amyloid A (SAA) with different concentrations are chosen as model system. Based on the antibody-antigen interaction, antibody-conjugated magnetic nanoparticles (MNPs), a-CRP MNPs, a-SAP MNPs, and a-SAA MNPs, can be used as the affinity probe to specifically extract antigens from plasma and quantitativly analyze multiple proteins. When applying this multiplex assay to human plasma analysis, distinct pattern of the protein profile can be used to differentiate healthy controls, patients with surgical operation of cardiac catheter, and gastric cancer patients.
Given the flexibility of manipulating functional groups on the nanoparticles, their low cost, and simplicity of the assay, this technique is capable for clinical proteomic diagnosis.||en_US|