Caspase-6 activity assays using the Mesoscale ELISA system 100 ng pure lamin A protein was subjected to digestion by different concentrations of caspase enzymes as indicated in the figures (0.05-1000 nM) in caspase cleavage buffer for 30 min at 37uC. The reactions were stopped by shock-freezing, and thawed samples were analysed with the Mesoscale ELISA system: 5 ml of each reaction, corresponding to 25 ng lamin A protein, were spotted onto Mesoscale ELISA plates. Samples were incubated at room temperature for 1 h, then 150 ml 5% BSA in PBS was added per well and the plate was again incubated for 1 h at room temperature. All wells were briefly washed 3 times with 150 ml PBS containing 0.05% Tween-20, and 25 ml antibody mix was added per well (cleaved lamin A antibody, Cell Signaling 2036, 1:100, goat anti-mouse sulfo-tag secondary antibody, MSD technology, 1:500 in 1% BSA/PBS). After 1 h incubation at room temperature, all wells were briefly washed 3 times with 150 ml PBS containing 0.05% Tween-20, and 150 ml 26 reading reagent (MSD technology) was added per well. The plates were then read on a Mesoscale platform electrochemiluminescence reader (MSD technology) according to manufacturer's instructions.