Microscope slides containing mouse thymus sections were xed with ice-cold acetone and stained with recombinant anti-mouse lamin B1 antibody (clone EPR22165-121; Abcam) consisting of 10% HiFCS and 0.2% triton-X 100 in PBS overnight followed by staining with 6.6 µg/ml anti-rabbit IgG conjugated to Alexa Fluor ® 555 (clone H + L, F(ab') 2 ; Cell Signalling Technology). Post wash, tissues were stained with 1 µg/ml DAPI solution (Thermo Fischer ™ ). Images were acquired using an Olympus IX71 inverted uorescence microscope at 10X and 40X magni cation and imaging analysis was performed using Image J software.