New IsoFlux Publication

“Circulating Tumor Cells as Potential Biomarkers in Bladder Cancer”

Journal of Urology - In Press

Alva (University of Michigan), et. al. 

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To explore the diagnostic use of circulating tumor cells (CTCs) in neoadjuvant bladder cancer patients using both enumeration and next-generation sequencing (NGS).

Materials and Methods

Twenty bladder cancer patients eligible for cisplatin-based neoadjuvant chemotherapy were enrolled in an IRB-approved study. Subjects had blood draws at baseline and following 1 cycle of chemotherapy. Eleven metastatic bladder cancer patients and thirteen healthy donors were analyzed for comparison. Samples were enriched for CTCs using a novel microfluidic collection device (IsoFlux System). CTC counts were analyzed for repeatability and compared with the FDA-cleared CellSearch CTC test. CTCs were also analyzed for mutational status using NGS.


Median CTC counts were 13 (Neoadjuvant - baseline), 5 (Neoadjuvant - follow-up), 29 (Metastatic), and 2 (Healthy). Concordance of CTC level (Low<10, Medium 11-30, High>30) across replicate tubes was 100% (n=15). In matched samples, the IsoFlux test showed 4/9 (44%) samples having 10 or more CTCs, while CellSearch showed 0/9 (0%). At time of cystectomy (4 months post-baseline), 3/3 patients (100%) with Medium/High CTC levels at both baseline and follow-up had unfavorable pStage (T1-T4 or N+). NGS analysis showed somatic variant detection in 4/8 patients using a targeted cancer panel; 8/8 (100%) of these were CTC Medium/High with a CTC fraction above 5% purity.


This study demonstrates a potential role for CTC assays in management of bladder cancer patients. The IsoFlux method of CTC detection exhibits increased sensitivity compared with CellSearch. An NGS assay is presented with sufficient sensitivity to detect genomic alterations in CTCs.



The IsoFlux System is about more than just capturing and counting circulating tumor cells. It is the critical link that allows genomic information from tumor cells to be obtained from a routine blood draw. The IsoFlux System has become the premier platform for molecular profiling of CTCs:

  • High sensitivity of CTCs across many tumor types
  • Tumor cell purity above 10% to meet the demands of NGS
  • Simple to operate, benchtop design
  • Consumable kits and protocols for NGS, qPCR, and immunofluorescence microscopy

Learn more about IsoFlux technology and the systems/kits available for your research.



Blood samples enriched with the IsoFlux System have the requisite tumor cell load and purity to be compatible with the latest next-generation sequencing (NGS) technologies, including targeted hotspot cancer panels that can survey hundreds of genes and thousands of mutations. The IsoFlux NGS DNA Kit was designed specifically to prepare IsoFlux samples for NGS with seamless efficiency. 

Download the IsoFlux Guide to NGS for Blood Biopsies

Download the IsoFlux NGS Application Note

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