Skip to Content

Circulating Tumor Cell Enrichment with Microbubbles

Bulk Methods Aren’t Good Enough for CTCs

Even after enrichment steps—such as Ficoll, lysis, or microfluidics—significant numbers of red blood cells (RBCs) often remain, which can prohibit effective downstream analysis of circulating tumor cells (CTCs).

CTCs enable a powerful new opportunity for liquid biopsies to diagnose, phenotype, and manage cancer noninvasively. The extreme rarity of these cells make it challenging for CTC isolation with millions of neighboring leukocytes and billions of red blood cells.

Why Do Too Many RBCs Cause Problems?

Microscopy image showing excessive red blood cells in a cancer cell sample (green cells).

When peripheral blood is harvested and cleaned up with a combination of density gradient and microfluidics, the sample may still contain over 90% RBCs. This is a problem.

In fact, in our conversations with researchers, we have heard firsthand how red blood cells get in the way:

  • Lower loading efficiency for single-cell genomics: When excessive RBCs are present, they reduce the number of wells loaded on sequencing systems.
  • Limits the integration of microfluidics: Labs are working to use new microfluidic system as a bulk enrichment step. However, excessive RBCs can still be present and reduce the ability to perform downstream testing.
  • Physically blocks culture: When working to culture rare cells, RBCs take up precious real estate on the plate, which can physically limit the growth of rare cells.

How Do Microbubbles Remove Unwanted RBCs?

With the Akadeum Human RBC Depletion Microbubbles, rare target populations are enriched in 10 minutes, allowing for higher efficiency of downstream single-cell analytics. Akadeum’s microbubbles provide a fast, easy, and gentle way to remove RBCs that persist after initial processing of blood or tissue.


Perform a quick clean up in 10 minutes before identifying, isolating, and analyzing CTCs. Save 30 minutes or more per prep.


Complete the whole process within a single tube. All you need is our microbubble reagent and gravity. No magnet is required: Save the $500–1000 you would spend on buying a magnet.

Highly Specific

Up to 99% removal of RBCs from samples in less than 10 minutes start-to-finish without losing precious CTCskeep the CTCs, lose the RBCs.

This flow cytometry diagram shows over 97% depletion of spiked red blood cells from PBMCs in 7 minutes. The RBC population is in the upper left of each diagram.

Want to start using microbubbles? Check out our Human RBC Depletion Microbubbles or contact us for more information.

Back to Top