Figure 4. Tools used for embedding of paraformaldehyde-fixed PDO.

200-μL pipet tips are modified to make embedding tips and embedding bottom-less barrels (A). A polypropylene 1.7-mL tube rack, covered by a sheet of Parafilm M, is used as a scaffold to place embedding bottom-less barrel where fixed organoids will be cast in along with embedding gel (pre-heated Bacto-agar) (B). To liquefy embedding gel, an aliquot of 5-mL Bacto-agar will be microwaved for 1 min in a 150-mL beaker containing 100-mL water.