Rare circulating tumor cells (CTCs) have been identified in peripheral blood from cancer patients and have been proved to be a main cause of metastatic disease. Current strategies for size based on isolation of CTCs has been technically challenged owing to their overlapped size value(e.g., CTCs ~16-20μm diameter and leukocytes ~8-14 μm). Here we describe the development of a unique microfluidic device, Taylor Gortler(TG) mixer, capable of efficient and selective separation of viable CTCs from peripheral whole blood samples, operated by the interaction of target CTCs with antibody (EpCAM)-coated microbeads under microfluidic channel, as a result the size of the CTCs will be increased. First of all, we used red-green fluorescence beads to evaluate the mixing efficiency of the device. And then, we have gotten binding efficiency by using breast cancer cell and anti-epithelial cell adhesion molecule(EpCAM) coated microbeads through TG mixer.