Molecular analysis of single- and bulk-enriched circulating tumor cells using the IsoFlux™ System


Circulating tumor cells (CTCs) are rare cells found in the blood of cancer patients with solid tumors and play a key role in cancer dissemination. There has been considerable interest in analyzing these cells as a potential source of clinically-actionable information relating to molecular prole of the patient’s disease. One of the current challenges in the eld is high recovery and purity of CTCs to enable molecular analysis.

The IsoFlux System (Fluxion Biosciences) provides high recovery of CTCs in a format optimized for downstream analysis. It provides three distinct methodologies for working with the CTCs after collection:

  1. Analyze the ‘bulk’ collection of CTCs to look at marker(s) present anywhere in the sample
  2. Analyze individual CTCs collected one at a time from the enriched fraction to examine cellular heterogeneity
  3. Analyze pools of individual CTCs to increase the sensitivity of the downstream analysis

Here we present analytical and clinical data using the above mentioned methods. A cohort of Her2+ breast cancer patients was analyzed for gene expression using the ‘bulk’ method.

Single cell analysis was performed using immunouorescence imaging as an orthogonal approach to measuring gene expression. To further demonstrate the single cell capability, a series of analytical (spiked) samples were prepared and analyzed using two orthogonal methods for mutational analysis, castPCR (Life Technologies) and targeted Next Generation Sequencing (NGS).