A new analytical platform for potential point-of-care testing of circulating tumor cells.

It is of significance to detect circulating tumor cells (CTCs) in whole blood using transportable instruments at the point of care to assist evaluating chemotherapeutic efficacy and recurrence risk of cancer patients. However, the current widely used detection methods either require expensive and complex equipments, need complicated enrichment steps, or produce high rates of false positive and/or negative results. Aiming for solving the two critical challenges involved in instrumentation miniaturization and simplification of sample preparation for POCT of CTCs without sacrificing the detection sensitivity and accuracy, this work reports a custom-built, automatic, large field-of-view microscopic CTC cytometer and a novel enrichment strategy based on a synthesized peptide ligand discovered from One-Bead One-Compound library screening. The custom-built microscope has compact size, low weight and efficient cost while still maintaining a detection limit of as low as 5 target objects. The simplified sample preparation utilized a novel peptide LXW7 functionalized to magnetic beads and allows for rapid, highly selective and sensitive detection of CTCs. This analytical platform may fulfill the unmet need for possible point-of-care CTC counting, and provide a new option for early diagnosis of cancers and convenient evaluation of chemotherapeutic efficacy and cancer recurrence.