Isolation and retrieval of circulating tumor cells using centrifugal forces : Scientific Reports : Nature Publishing Group

Isolation and retrieval of circulating tumor cells using centrifugal forces : Scientific Reports : Nature Publishing Group

This paper is from Clearbridge Biomedics, manufacturers of a commercial CTC system (CTC chip), which    is used to isolate CTCs based on physical properties (size and deformability)

The present paper uses inertial microfluidics (explained here and here ), which uses a spiral channel and the centrifugal forces generated within the channel to separate cells based on their physical properties.

http://www.nature.com/srep/2013/130212/srep01259/carousel/srep01259-f1.jpg

Performance Summary:
> 85% recovery
> positive CTCs enumeration in all samples from patients with metastatic lung cancer (n = 20; 5–88 CTCs per mL
> throughput: 3ml/hr.

Commentary:
This work is concurrently ongoing at Clearbridge and University of Cincinnati (now seemingly independently, though the source of origin is university of cincinnati). Prof. Ian Papautsky from the University of Cincinnati has pioneered inertial microfluidics-based cell sorting for a number of years, leading to many publications.

Focus review 2013: Label free microfluidic technologies for isolation of circulating tumor cells (CTCs)

Label-free isolation of circulating tumor cells in microfluidic devices: Current research and perspectives

This paper is quite comprehensive in covering the many label free approaches to CTC isolation reported so far, including, filters, accoustophoresis, magnetophoresis, etc.

The general recommendation of the paper is towards adoption of these technologies for clinical use.

undoubtedly, there are several advantages to label-free isolation of CTCs, specially filtration techniques, which are simple, inexpensive, fast and easy to use. However, there are some important limitations that need to be considered,  which I was hoping the paper would shed light upon, but didnt.

the general limitations of filtration techniques are listed here.

It was also recently reported that the deformability of tumor initiating cells is less differentiated from normal blood cells. This makes the sized and deformability based techniques vulnerable to missing these important subtypes of CTCs. This is covered here 

High-purity and label-free isolation of circulating tumor cells (CTCs) in a microfluidic platform by using optically-induced-dielectrophoretic (ODEP) force

pubs.rsc.org/en/content/articlepdf/2013/lc/c3lc41256c

High-purity and label-free isolation of circulating tumor cells (CTCs) in a microfluidic platform by using optically-induced-dielectrophoretic (ODEP) force - Lab on a Chip (RSC Publishing)

High-purity and label-free isolation of circulating tumor cells (CTCs) in a microfluidic platform by using optically-induced-dielectrophoretic (ODEP) force - Lab on a Chip (RSC Publishing)