Grow cells on coverslips in 6-well plates
Remove coverslips using a fine-tipped forceps when desired cell density is reached, and put in coverslip rack, cell side facing "cells" label on holder.
Put holder in 100 mL beaker containing ~60 mL PBS with a tiny stir bar. Rinse by stirring for ~5 minutes.
Transfer holder to a second 100 mL beaker containing ~60 mL of fixative. Fix with stirring for ~10 minutes
Transfer holder to a 3rd beaker containing PBS-Tw-Az. Rinse by stirring for ~5 minutes.
Repeat with another beaker of PBS-Tw-Az.
Stain or mount coverslips right away, or store them in the holder in a brown jar with fresh PBS-Tw-Az. They may last up to a month in the refrigerator. Longer than that, they will start to fall off the coverslip.