Nova nanosem 650 field emission scanning electron microscope

Samples were fixed in 2.5% glutaraldehyde (Tousimis, Rockville, MD, USA) in 0.1 M sodium cacodylate buffer for 2 h followed by 2 × 10 min washes with 0.1 M sodium cacodylate buffer. Samples were then immersed in an aqueous solution of 1% osmium tetroxide (Electron Microscopy Sciences, Hatfield, PA, USA) for 1 h followed by 2 × 10 min washes in sodium cacodylate buffer and then dehydrated by a series of 10 min each washes in 10%, 30%, 50%, 70%, 90%, and 100% ethanol. Finally, all substrates were allowed to fully air dry before sputter deposition of 10 nm gold/palladium film and imaging with Nova NanoSEM 650 Field Emission Scanning Electron Microscope (FEI Co., Hillsboro, OR, USA).

Cells on their substrate were fixed for 2 hrs with 2.5% glutaraldehyde in 0.1M sodium cacodylate buffer. Next, 2x10 min washes in 0.1 M sodium cacodylate buffer were performed. Samples were then immersed in 1% osmium tetroxide for 1 hr followed by 2x10 min washes in 0.1 M sodium cacodylate buffer. Samples were then dehydrated by a series of 10 min washes in 10%, 30%, 50%, 70%, 90%, and 100% ethanol. Samples were then allowed to air-dry and were then sputter-coated with a 10 nm layer of gold. Cells on their substrate were then mounted on a stub using silver adhesive tape. Imaging was performed with a Nova NanoSEM 650 Field Emission Scanning Electron Microscope (FEI Co.).