Background/aim: A multistep sorting method for enrichment of rare cells, such as circulating tumor cells, in the blood without cumbersome pretreatments required by most flow cytometry-based methods, which lead to high cost and decreased detection efficiency, was developed.
Materials and methods: After only hemolysis and cell staining, cancer cells are enriched by repetitive sorting (3×) based on nuclear-positive, cytokeratin-positive, and CD45-negative expression.
Results: Experiments using spikes of PC-9 cells showed a mean recovery of 65% and mean purity of 83%, which was retained up to 72 hours after blood draw using preservative tubes. Significant differences in expression level of programmed death-ligand 1 or vimentin were observed between high- and low-expressing cell lines, concurrently with enrichment. Next-generation sequencing analysis of recovered PC-9, A549, and MDA-MB231 cells successfully detected all known mutations.
Conclusion: This novel isolation method applicable for preserved samples with sufficient recovery and purity may be substantially beneficial for recovering cells for subsequent molecular analysis.
Keywords: Cancer cell; PD-L1; circulating tumor cell; liquid biopsy; microfluidic chip cell sorter; multistep sorting.
Copyright © 2022 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.