Fig. 3. Micropipette aspiration of swollen and unswollen nuclei. (A) Bright-field and DNA/RNA (labeled with YO-PRO) fluorescence images of either unswollen or swollen nuclei aspirated into a micropipette (inner radii R_p=98 µm and 139 µm, respectively). The unswollen nucleus shows deformation of the nucleoplasm coincident with the nuclear envelope. The nucleoplasm of the swollen nucleus remains external to the micropipette. (B) Representative data of Laplace tension, a function of incremental aspiration pressure, versus aspirated length of unswollen () and of swollen () nuclei yield similar slopes (see Table 1). Aspiration is reversible since decreasing the aspiration pressure () follows the same trend as increased pressure (,).