Abstract 6605: Automated isolation and identification of circulating rare cells from blood samples using a label-free rare cell isolation platform - the Genesis System with Celselect Slide technology
Authors: Kang Yoon-Tae , Pusod Errile , Crudgington Ally , Bodunrin Abiodun , Bosio Nick , Chan Susana , Coe David , Racey Michelle 
Published: April 2023

Introduction: Isolation and identification of circulating tumor cells (CTCs) offers a promising non-invasive diagnostic tool for cancer research, but significant technical hurdles have made practical application challenging. Recent studies have shown that CTCs undergo cellular changes, such as an epithelial-mesenchymal transition (EMT), with disease progression and metastasis, implying the heterogeneity of the tumor cell population in circulation. Systems for CTC isolation are often limited by a requirement for epithelial markers or separate systems for identification of CTCs. As such, an automated platform that successfully isolates both epithelial and mesenchymal cells and enables identification of cells is necessary for successful study of CTCs. The Genesis System from Bio-Rad™ Laboratories, Inc. isolates rare CTCs based on size and deformability. It also enables users to identify isolated cells through use of an on-slide immunofluorescence (IF) staining workflow, which minimizes sample manipulation and potential sample loss.

Methods: In order to achieve high-throughput label-free CTC isolation, the Genesis System uses Celselect Slides™. Each slide contains 56,400 individual microchambers to capture CTCs while maintaining viability. This Celselect Slide technology can be used for either enrichment or enumeration protocols. For this study, enumeration protocols were performed to capture and identify CTCs using on-slide IF staining. Enrichment protocols were utilized to capture, enrich, and retrieve CTCs for downstream applications. The performance was evaluated using a breast cancer cell line, MCF-7, spiked into whole blood from healthy donors.

Results: The slide isolated 83.95 ± 10.25% of spiked cancer cells in blood samples at a concentration of 10-250 cells/ml. During the CTC enrichment procedure, 99.92% of blood cells were eliminated. Afterwards, 70% of the isolated CTCs were successfully released from the slide and over 92% of the released cells remained viable.

Discussion and Conclusion: We present a fully automated platform to isolate and identify CTCs using on-slide immunofluorescence staining, which minimizes inevitable cell loss during the workflow. Captured cells can be retrieved for downstream applications to facilitate discovery of unknown CTC functions and their clinical relevance in cancer research. The wide range of possible downstream applications include Droplet Digital™ PCR, quantitative PCR, western blot assays, bulk/single-cell genomics, cell culture, fluorescence in situ hybridization, and RNA-Seq. Additionally, the design of the system is amenable to other biofluids which may be utilized for liquid biopsies. The Genesis System with Celselect Slide technology offers a powerful diagnostic tool to monitor disease progression and personalized treatment.

Citation Format: Yoon-Tae Kang, Errile Pusod, Ally Crudgington, Abiodun Bodunrin, Nick Bosio, Susana Chan, David Coe, Michelle Racey. Automated isolation and identification of circulating rare cells from blood samples using a label-free rare cell isolation platform - the Genesis System with Celselect Slide technology. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6605.