Bdh1101

24×55mm Glass coverslips (Globe Scientific, NJ, USA) were functionalized with glutaraldehyde (A17876, Alfa Aesar, MA, USA) to promote COL1 attachment to the coverslip via amine-aldehyde- amine coupling. Coverslips were functionalized as described by Syga et al ^{72 (link)}. Briefly, coverslips were sonicated in 70% ethanol for 5 min followed a rinse in DI water for 1 minute and then dried using pressurized air. The clean coverslips were heated at 100°C for 5 min to ensure that they were completely dry.
To attach amine groups on the surface of the coverslips, the glass surface was first activated by exposing it to a corona discharge wand for 1 min (BD-20AC, Electro-Technic Products, IL, USA). The corona-discharge treated coverslips were immediately dipped in a solution of 2% aminopropyltriethoxysilane (APTES) (80370, Thermo Scientific, MA, USA) in acetone (BDH1101, VWR, PA, USA) for 10 seconds, rinsed with acetone for 30s, and dried under an air stream. A 5% aqueous glutaraldehyde solution was prepared and pipetted over the silanized coverslips. After 30 min, the coverslips were rinsed with DI water for 1 minute, and dried using air. The prepared coverslips were then stored for use up to 3 days in clean petri dishes.