Don't have a ref in mind but we used to fix and prepare the cells on the inserts followed by mounting a dry cut out on a stemmed disk using double-sided tape or a commercially available circle that transferred adhesive to the disk. This is best I recall: Cells were fixed at 4 degrees C in 2.5% glutaraldehyde in 0.15 M HEPES, washed twice with buffer for 5 min, and then dehydrated in 70, 80 and 95% ethanol for 15 min each at room temperature. Cells were immersed in 100% ethanol three times for 10 min and critical point dried in liquid CO2 before sputter coating with gold.