Fig. 2: The workflow for precise micro-compartmentalization of the tissue and the procurement of spatially resolved micro-specimens.

a The 3D-printed micro-scaffold with narrow edges to achieve precise tissue compartmentalization (scale bar: 400 µm). b The assembly of the 3D-printed pressurization module with the stack of micro-scaffold, tissue slice, and the supporting matrix (from upper to lower), to enable precisely-regulated and uniform pressurization across the entire tissue slice. The detailed pressurization procedure is shown in Supplementary Movie 1. c The schematic procedure for robust tissue micro-compartmentalization followed by efficient procurement of micro-specimens. A precisely-regulated pressure is applied on the micro-scaffold, which uniformly immobilizes (1) and then compartmentalizes the tissue slice with elevated pressure (2). Next, a 3D-printed piston array with breakable pistons is inserted into the micro-scaffold to push the micro-specimens out of the micro-wells, detailed in Supplementary Fig. 4 (3). Then, the micro-specimens are transferred to sample tubes (4). d The photos of a brain tissue slice before (left) and after (right) the compartmentalization. The entire tissue slice was uniformly and completely compartmentalized without any left-over tissue, while the spatial information was faithfully maintained. e Exceptional linearity between cumulative protein amounts versus cumulative numbers of micro-specimens, indicating excellent reproducibility and robustness of both micro-compartmentalization and sample preparation, which sets a solid foundation for reliable protein mapping.