Bead affinity chromatography in a temperature-controllable microsystem for biomarker detection.

This paper describes a temperature-controllable bead affinity chromatography (BAC) in a microsystem for biomarker detection, and preparing samples for matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analysis. Cancer marker proteins were captured in the microsystem by BAC with RNA aptamer-immobilized microbeads. The captured proteins were then denatured and released from the microbeads by controlling temperature. The microsystem consists of a microreactor for trapping microbeads and a temperature control unit for thermal treatment of the trapped beads. We used polymethylsilxoane or single crystalline silicon in fabricating two different types of reaction chamber to compare the differences in performance originated from the materials. Carcinoembryonic antigen was concentrated and purified from human serum using the microsystem and detected by MALDI-TOF MS to demonstrate the usefulness of the microsystem. The microsystem simplifies a sample preparation process required for protein analysis and cancer biomarker detection, which will accelerate the process of cancer research.