Circulating tumor cells (CTCs) have shown incredible promise in clinical and diagnostic applications. CTC-based liquid biopsies can aid in earlier diagnosis, identify the stage of disease, guide therapeutic aggressiveness, and be used to monitor response to treatment. While CTCs hold incredible promise in these areas, there are inherent limitations that hinder realization of the full potential of CTC-based liquid biopsy tests. The rarity of CTCs is one of the most significant factors limiting clinical utility. A standard 10-mL blood draw may simply not contain the number of CTCs needed to yield meaningful results. One method to analyze greater blood volume is by leukapheresis. While clinical leukapheresis can enrich mononuclear cells, including CTCs, from almost the entire volume of a patient’s blood, most downstream CTC enrichment methods are not compatible with leukapheresis material as a starting sample. To overcome these compatibility issues, Akadeum Life Sciences has developed a novel and proprietary Buoyancy Activated Cell Sorting (BACS™) microbubble platform that can be functionalized to selectively enrich biological samples for target cell populations using a fast, easy protocol that is exceptionally gentle on delicate cells of interest. Akadeum’s low-density BACS microbubbles are mixed into the sample where they quickly engage their targets and naturally float them to the surface for removal. This straightforward approach is elegant in simplicity and powerful in application, offering some of the fastest and most gentle isolations available. In this study, we demonstrate a protocol for the depletion of white blood cells (WBCs) & residual red blood cells (RBCs) from leukapheresis material via microbubbles. This novel protocol reveals a > 99% combined depletion of residual RBCs and WBCs, providing over 120-fold enrichment of tumor cells. Importantly, this protocol delivers exceptional yield with > 99% retention of the target tumor cells. This optimized workflow delivers an enriched and viable population of untouched and unaltered CTCs for downstream use.

Citation Format: Edward Grimley, Jon Roussey, Chia Ku, Carolina Livi, Nadia Petlakh-Co, Casey Wegner, Brandon H. McNaughton. Enhanced isolation of circulating tumor cells from leukapheresis material enabled by Akadeum microbubbles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5167.