Table 1: Cytogenetic characteristics of RKO cell line compared to MSI and MSS cell lines.

Cell lineAneuploid IndexVariability of centromere numberRearranged Chromosomes by M-FISH/SKYCopy number changes by CGH

MSI cell lines1–8 (3.1)1–3 (2)0–5 (2.7)0–4 (2.4)
MSS cell lines8–19 (14.2)6–30 (15.4)9–24 (15.8)11–30 (19.4)

The aneuploid index was calculated as the sum of all the consistent chromosomal gains or losses present in the karyotype. Thus, for each monosomy or each trisomy present, a score of 1 was contributed to the aneuploid index. The aneuploid index is different from the modal chromosome number because of cell to cell variability in the presence or absence of a specific chromosome. The variability of centromere numbers was calculated by counting in each of the examined metaphases the number of copies of each centromere, whether in normal or rearranged copies of a chromosome; noting the percentage of metaphases that have deviations from the modal centromere number; and averaging over all centromeres. The data of the MSS and MSI cell lines, shown as range followed by average, were pooled from the published literature [8, 17, 18] omitting the newest duplicate data in chronological order and excluding the nonclassical cell lines C70, HCA7, and LS411.