Highly Sensitive Protein Quantification by Direct Kinetic Fingerprinting of Single Protein Molecules

Abstract

The sensitive and accurate quantification of protein biomarkers plays important roles in early stage diagnosis of disease. However, existing methods for protein quantification exhibit significant background signal from the nonspecific binding of detection probes to assay surfaces or matrix components. As a result of this non-specific signal, they generally do not achieve single-molecule sensitivity, and require stringent washing to maximize sensitivity. To filter out this nonspecific signal and to thereby increase the sensitivity and accuracy of protein quantification, here we have applied single-molecule kinetic fingerprinting with dynamically binding probes to the problem of protein detection.