Detecting circulating tumor cells via laser scanning

Circulating tumor cells (CTCs) are generally considered as seeds for metastases, serving as a clinical biomarker for cancer diagnosis and prognosis. However, they are difficult to detect due to their low content in the blood of cancer patients. Consequently detection of CTCs normally requires an antibody-mediated biological enrichment process, which is very time-consuming. In this work, we demonstrate an antibody-free, efficient, fast and cost-effective way of detecting CTCs. That is, CTCs are physically isolated by size using filtration, and subsequently characterized in an optical way via laser scanning. The filtered and stained blood sample, which is placed on a moving and spinning stage, is illuminated by a 405nm diode laser. Then the scattered optical signals are focused using an ellipsoidal mirror for a better photon collection. Eventually CTCs in the scanning image are identified and counted by the clustering algorithm. Our method has advantages in high efficiency and low cost, holding great promise for early diagnosis and prognosis prediction of cancer patients.