Fig. 1: GelMap enables intrinsic calibration and deformation mapping in expanded hydrogels.

a, Schematic of the general GelMap workflow. b, Representative images of the indicated steps of GelMap. (i) An 18-mm glass coverslip patterned with fluorescent laminin and amplified with antibody labeling (orange) shown before gelation. (ii) The same coverslip after digestion of a locally polymerized gel using a silicone mold in the middle of the coverslip (6 mm diameter), showing complete transfer of protein pattern from the coverslip. (iii) The polymerized and digested gel corresponding to the region indicated with gray circle in (ii) was expanded 3× and imaged, showing anisotropic deformation. (iv) The resulting acquisition was used for landmark-based registration to the pre-expanded image in (i) for correction of local deformations in the gel. c, Top: U2OS cells stained for tubulin (cyan) cultured directly on laminin-patterned GelMap coverslip and imaged before expansion. Bottom: Region marked in top image after expansion (expansion factor, 9.6×) using TREx, corrected using GelMap. Scale bars, 2 mm (b), zoomed regions 400 µm; 40 µm (c). Scale bars in expanded samples reflect pre-expansion sizes.