Karyotype arrays of the native and a methotrexate-resistant variant of the near-triploid cervical carcinoma MS-751. The table of the chromosome and the arrays of the two MS-751 variants show that the chromosome number of the native MS-751 variant is 75±10 and that of the methotrexate-resistant variant is 75±5. They are thus both quasi-clonal. The table also shows that the copy numbers of 60-100% chromosomes were clonal forming parallel lines in the karyotype arrays. Non-clonal chromosomes were intact chromosomes with near-clonal copy numbers and new non-clonal marker chromosomes, which were found in nine of 20 cells of the native MS-751 variant and in 11 of 20 cells of the drug-resistant clone. Comparison of the arrays of the two MS-751 variants shows at a glance that the two variants are karyotypically closely related. They differed from each other in the copy numbers of five clonal intact chromosomes, and in three 30–90%-clonal native MS-751-specific markers, and in four 80-90%-clonal methotrexate resistance-specific markers. By chance, the four clonal methotrexate-specific MS-751 marker chromosomes, flagged with asterisks, were all found in one non-clonal cell of the native MS-751 carcinoma (See also section three). Comparison of the MS-751 arrays with the arrays of the eight carcinomas shown in Figures 6, 7, 8, 9, 10, 11, 12 and 13 reveals again at a glance that all nine carcinomas have distinct individual clonal karyotypes. Note, about 25 non-clonal marker chromosomes of the 20 karyotypes of the MS-751 variants listed in the table are not shown in the graphs to allow sufficient resolution for the clonal chromosomes.