Pdms sylgard 184 silicone elastomer and curing agent

Procedures to deform embryos of the sea urchin (Chang et al., 2014 (link); Minc et al., 2011 (link); Tanimoto et al., 2016 (link)) were adopted to deform the C. elegans eggshell. A SU-8-positive master containing tens of posts that were 24 μm in height and of different shapes was first constructed by microlithography. A 10:1 mixture of PDMS Sylgard 184 silicone elastomer and curing agent (Dow Corning) was poured onto the master, and air bubbles inside the mixture were removed using a desiccator vacuum for 30 min; then, the mixture was baked at 65°C for 2 h. The replica was cut, peeled off the master, and activated with plasma cleaner (PDC-32G; Harrick Plasma, Ithaca, NY). C. elegans embryos were dissected from adult worms and collected in M9 buffer (Brenner, 1974 (link)). The two-cell stage embryos were transferred on to the micro chamber by using a mouth pipette and placed into the target chamber via manual handling using an eyelash bar in M9 buffer. A glass coverslip (18×18 mm²) was then placed on top of the solution, and buffer was gently sucked from the slides of the coverslip with a paper towel to slowly push the embryos into the chamber. The embryos were imaged at the four-cell stage.