BOOST: a robust ten-fold expansion method on hour-scale.

Expansion microscopy enhances the microscopy resolution by physically expanding biological specimens and improves the visualization of structural and molecular details. Numerous expansion microscopy techniques and labeling methods have been developed over the past decade to cater to specific research needs. Nonetheless, a shared limitation among current protocols is the extensive sample processing time, particularly for challenging-to-expand biological specimens (e.g., formalin-fixed paraffin-embedded (FFPE) sections and large three-dimensional specimens). Here we present BOOST, a rapid and robust expansion microscopy workflow that leverages a series of microwave-accelerated expansion microscopy chemistry. Specifically, BOOST enables a single-step 10-fold expansion of cultured cells, tissue sections, and even the challenging-to-expand FFPE sections under 90 minutes. Notably, BOOST pioneers a 10-fold expansion of large millimeter-sized three-dimensional specimens, previously unattainable to the best of our knowledge. The workflow is also easily adaptable based on stable and common reagents, thus boosting the potential adoption of expansion microscopy for applications.