Determination of Hepatocellular Carcinoma Serum Polypeptide Based on Antibody Preconcentration Coupled with Mass Spectrometry

Polypeptide antibody pre-concentration method coupled with mass spectrometry detecting was established for the determination of serum polypeptide.Polypeptide was captured by agarose beads followed by binding of specific polyclonal antibodies from serum.After timed washing steps,the remaining bound polypeptides were eluted from the beads and detected by matrix-assisted laser desorption/ionization time-of-flight(MALDI-TOF) mass spectrometry(MS).We optimized a protein A agarose bead-based platform amenable to high throughput peptide capture followed by mass spectrometry can achieve ion signal,with precision(RSD12%) and accuracy(about 10% of relative error) sufficient for quantifying biomarkers in the physiologically relevant nmol/L range.The method for the detection of peptide 5(pep5) in the clinical hepatocellular carcinoma serum had sensitivity of 78.0% and specificity of 90%.The method is appropriate for the detection of low concentration biomarkers in clinical samples,and it will be significant for earlier diagnosis of cancers.