In this video, we describe a method called expansion pathology, a variant of expansion microscopy, wherein the clinical tissue specimens are chemically expanded using a polymer network for microscopic examination of nanoscale structures.
Protocol
1. In Situ Polymerization of Specimens Incubate the specimen in an anchoring solution. Prepare the anchoring solution (typically 250 µL is enough to cover the tissue section) by diluting the AcX stock solution in 1x PBS to a concentration of 0.03 mg/mL for samples fixed with non-aldehyde fixatives or 0.1 mg/mL for samples fixed with aldehyde fixatives, which have fewer free amines available to react with AcX. Place the slide in a 100 mm Petri dish and pipette the a…
Representative Results
Figure 1: Gelation chamber for pathology samples. (A) Two spacers, such as two pieces of #1.5 cover glass cut with a diamond knife, are placed on either side of the tissue after incubating the sample in gelling solution at 4 °C. The spacers should be thicker than the tissue slices, to prevent compression of the sample. (B) A lid, such a…