Optimizing CTC Isolation and Characterization

Eighteen samples (10 samples from NSCLC patients and 8 samples from breast cancer patients) were used to compare the efficacy of the CanPatrol CTC enrichment technique before and after optimization. For each sample, 5 ml of blood was used for CTC isolation and characterization using each method. Before optimization, a combination of the CD45+ magnetic bead separation and filtration methods was used for CTC isolation, and an immunostaining method was applied for CTC characterization. The protocol of this method has been described before [23 ]. To classify CTCs using EMT biomarkers, an antibody cocktail consisting of anti-EpCAM (R&D, Minneapolis, USA), anti-CK8/18/19 (R&D, Minneapolis, USA), anti-vimentin (BD Bioscience, San Jose, USA), anti-twist (BD Bioscience, San Jose, USA) and anti-CD45 (Surexam, Guangzhou, China) was used to stain the CTCs.