Isolation of cancer stem cells from cultured breast cancer cells and xenografted breast tumors based on aldehyde dehydrogenase activity

Methods Cell Biol. 2022;171:111-125. doi: 10.1016/bs.mcb.2022.04.006. Epub 2022 Jun 6.


The heterogeneity of breast tumors is a major factor in the development, progression, and therapeutic response of breast cancer. In terms of therapy resistance, a subset of tumor cells commonly referred to as cancer stem cells (CSCs) or tumor initiating cells (TICs) have a prominent role. These cells have inherent increased tumorigenicity, self-renewal and differentiation capacity, and mechanisms for chemotherapy and radiation resistance. The importance of CSCs/TICs in cancer makes isolating and studying these cells via reliable methods critical. CSCs/TICs can be enriched for by discrete markers. Increased aldehyde dehydrogenase (ALDH) activity as detected by the AldefluorTM assay is a commonly used method. In this chapter, we describe the detailed methods for identification and isolation of putative CSCs/TICs from cultured cells and xenografted breast tumors using the AldefluorTM assay and describe the importance of the ALDH isoforms in breast cancer.

Keywords: ALDH1A1; ALDH1A3; Aldefluor assay; Breast cancer; Cancer stem cells; Fluorescent associated cell sorting (FACS).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehyde Dehydrogenase
  • Breast Neoplasms* / pathology
  • Cell Line, Tumor
  • Female
  • Heterografts
  • Humans
  • Neoplastic Stem Cells / pathology


  • Aldehyde Dehydrogenase