T1588

Two chambers with microwells and dams were fabricated on a standard microscope glass slide by casting a polyacrylamide gel against the wafer with SU-8 features. The final gel with 8 %T and 2.7 %C was chemically polymerized from a stock 30 %T, 2.7 %C acrylamide/bis-acrylamide solution (A3699; Sigma) with a 3 mM N-[3-[(3-Benzoylphenyl)formamido]propyl] methacrylamide (BPMAC, custom synthesized by PharmAgra Laboratories) and 75 mM Tris HCl pH 8.8 (T1588; Teknova). Ammonium persulfate (A3678; Sigma) and TEMED (T9281; Sigma) were used as reagents for chemical polymerization. The dried gel’s thickness was measured by using Sloan Dektak 3030. To hold the cell suspension inside each chamber during centrifugation, a polyester film (GelBond®; Lonza) was used as a lid (Fig. S1^†). Holes were punched in the lid using a Herm Sprenger Revolving Hole Punch (#10809). A liquid superglue (Loctite) was applied along the edges between the glass slide and the lid to act as a seal.

Acrylamide/Bis-acrylamide, 30 w% solution (Sigma A3699), 1.5 M Tris–HCl, pH 8.8 (Teknova T1588), Tris HCl Buffer 0.5 M solution, sterile pH 6.8 (Bio Basic SD8122), Ammonium persulfate (Sigma A3678), UltraPure 10% SDS (Invitrogen 15553-027), TEMED (Thermo Fisher Scientific 17919), Dithiothreitol (DTT) (BIO-RAD 1610610) Tris Base (Fisher Bioreagents BP152), Glycine (Fisher Bioreagents BP381), 4X Laemmli sample buffer (BIO-RAD 1610747), TWEEN 20 (Sigma P9416), Mini Trans-Blot filter paper (BIO-RAD 1703932), Nitrocellulose Membranes 0.45 μm (BIO-RAD 1620115), EveryBlot Blocking Buffer (BIO-RAD 12010020), Clarity Western ECL Substrate (BIO-RAD 170-5060).