1：Experimental Design and Method Selection:

The study designed a modified fiber probe sensor (MFP sensor) with a sharp needle tip and reduced stiffness for in situ measurement of nuclear mechanics using atomic force microscopy (AFM). The Hertzian model was used for data analysis.

2：Sample Selection and Data Sources:

NIH3T3 cells were cultured in different states (non-adherent, adherent, early apoptotic) using DMEM medium with FBS and penicillin-streptomycin. Cells were stained with AO/EB for viability assessment.

3：List of Experimental Equipment and Materials:

AFM system, MFP sensor, xyz micropositioning stage (MS-I, Newpoint, USA), xyz nanopositioning stage (nPoint NPXY60Z20-257, USA), optical beam deflection system with laser generator (57-106, Edmund, USA) and PSD (QP10-6 TO8s SD2, First Sensor), dual oscillation controller (Dual-OC4, Nanonis GmbH), optical microscope, FIB/SEM system (Helios NanoLab 600i), standard silicon bead, Petri dish (Cell Culture Dish 430165, Corning), AO/EB staining solution (CA1140, Solarbio).

4：Experimental Procedures and Operational Workflow:

Cells were cultured and stained; MFP sensor was fabricated using FIB etching and assembled; stiffness and sensitivity were calibrated; force-displacement curves were measured on cells in different states using the AFM setup with top-view and side-view visions.

5：Data Analysis Methods:

Force-displacement data were analyzed using the Hertzian model for cylindrical tips to calculate Young's modulus, with Poisson's ratio assumed as 0.5.