Microfluidic, marker-free isolation of circulating tumor cells from blood samples

Nat Protoc. 2014 Mar;9(3):694-710. doi: 10.1038/nprot.2014.044. Epub 2014 Feb 27.


The ability to isolate and analyze rare circulating tumor cells (CTCs) has the potential to further our understanding of cancer metastasis and enhance the care of cancer patients. In this protocol, we describe the procedure for isolating rare CTCs from blood samples by using tumor antigen-independent microfluidic CTC-iChip technology. The CTC-iChip uses deterministic lateral displacement, inertial focusing and magnetophoresis to sort up to 10⁷ cells/s. By using two-stage magnetophoresis and depletion antibodies against leukocytes, we achieve 3.8-log depletion of white blood cells and a 97% yield of rare cells with a sample processing rate of 8 ml of whole blood/h. The CTC-iChip is compatible with standard cytopathological and RNA-based characterization methods. This protocol describes device production, assembly, blood sample preparation, system setup and the CTC isolation process. Sorting 8 ml of blood sample requires 2 h including setup time, and chip production requires 2-5 d.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Separation / methods*
  • Humans
  • Insect Proteins
  • Magnets
  • Microfluidic Analytical Techniques / methods*
  • Neoplastic Cells, Circulating*


  • ICHIT protein, Anopheles gambiae
  • Insect Proteins