Fig. 1

Isolation of mammary epithelial cells (MEC), mesenchymal cells (MES) and adipose-derived stem cells (ADSC) from human fat tissue and cell type identification of normal mammary cells (NORMA)4. a Breast epithelial and mesenchymal cells were isolated from normal and tumor tissue and ADSC were isolated from adipose tissue. Isolation of MEC and MES resulted in two critical fractions, a pellet (P1) and supernatant (S1), which were the basis for the fractionation of epithelial (first row) and mesenchymal cells (second row), respectively. The P1 fraction was enriched with large epithelial extralobular or intralobular duct-like glands and with further fractionation steps (P4) we observed enrichment of single epithelial cells, whereas the P6 was enriched with mesenchymal cells. The pre-coating of the cell culture dishes with collagen enhanced the attachment and proliferation of the epithelial cells, where cells grew exponentially up to 30 days as epithelial cell clusters. Immediately after isolation ADSC were seeded in cell culture flasks (third row, first left). At 24 h after isolation (third row, middle) over 95 % of rounded cells became adherent. Cellular morphology changed rapidly within the next few days to an elongated shape (third row, right). Scale bar 100 μm. b DNA fingerprinting used for cell line identification. NORMA4 primary breast tissue and the isolated MEC and MES primary cell lines had 100 % congruence for all 21 short tandem repeats (STRs). Lines on each graph represent STRs: blue, green and black indicate identities between the different samples