To begin pour two grams or about one milliliter of negative PDMS precursor solution onto one well of a six well square parametal master mold. After covering the master mold with PDMS, place the plate in a vacuum desiccate to degas the solution. Next, place the plate in an oven at 60 degrees Celsius for 24 hours to cure the PDMS.
Once PDMS cures but is still warm, use a spatula to carefully remove the PDMS mold from the master mold. Then with a biopsy punch, cut it into a 35 millimeter diameter slab. Place the properly cut PDMS mold in a Petri dish and cover it with the lid to continue curing it at room temperature for an additional 24 hours.
To prepare the positive PDMS mold place a 35 millimeter slab of the negative PDMS mold in a 35 millimeter Petri dish with the textured micro wells facing up. Pour 2.5 grams or about 1.2 milliliters of positive PDMS precursor solution onto the negative mold in the Petri dish. Degas the precursor solution for 30 minutes before placing it into the oven at 60 degrees Celsius for three to four hours.
After curing, remove the molds from the Petri dish. Immediately peel the positive mold from the negative mold. Use a 10 millimeter biopsy punch to cut the positive molds into slabs.
Next, use tweezers to gently dip the flat side of each 10 millimeter positive mold into the pre-prepared PDMS glue precursor solution. Carefully place one mold per well in a well of a 48 well plate. Gently press each mold to glue it to the well bottom.
Incubate the assembled plate at 60 degrees Celsius for four to 24 hours to cure the glue.
