3D nuclear staining of telomeres and DNA in U-HO1-PTPN1 RS-cells. A. Representative 2D Z-stack image no. 37 out of 80 shows a tri-nuclear RS-cell composed of two large and one small telomere-poor "ghost" satellite nucleus. Arrow identifies a mid-sized telomere also shown in B and C. B. 3D reconstruction in surface mode reveals relatively few (compared to cellular volume) mid-sized and short telomeres. Very short telomeres including t-stumps are rare. C. Combined 3D nuclear staining confirms 3D telomere dynamics identical to those observed in precursor H-cells (see Figure 4).