In solid tumours, a discreet population of tumour associated cancer stem cells (CSCs) are proposed to drive and sustain tumour development and be responsible for tumour relapse. Colorectal cancer stem cells express cellspecific surface markers, including amongst others, CD133, EpCAM, CD44, CD166, and CD94f. In the present study, we characterised cell populations in the human colon adenocarcinoma cell lines, SW1116, HT29 and DLD1, expressing both CSC markers CD133 and EpCAM. These cell lines represent early, mid and late stages of colorectal tumours, respectively. Up to 10 7 SW1116, HT29 and DLD1 cells, co-stained with anti-CD133 and anti-EpCAM, were evaluated using flow cytometry. We report here progressively increasing proportions of cells co-expressing the CD133/EpCAM epitopes in the respective cell lines. In the SW1116 cell line, 2.42 ± 0.20 percent of cells were CD133+EpCAM+, in the HT29 cell line, 5.13 ± 0.17 percent of cells were CD133+EpCAM+, and in the DLD1 cell line, 10.30 ± 0.2 percent of cells were CD133+EpCAM+. These data suggest the frequency of CD133/EpCAM marker expression may be associated with tumour stage and aggression. Carlsbad, United States) and 10 000U/ml penicillin with 10 000μg/ ml streptomycin (Lonza, Basel, Switzerland). The cells were incubated at 37°C with an atmosphere of 5% CO 2 and 90% humidity and were passaged at 70% confluency, every 2-3 days. Journal of Tissue Science & Engineering