Ewa Blaszczyk, Danuta Mielzynska-Swach: Micronucleus assay in epithelial cells from the oral cavity and urinary tract in female smokers and non-smokers. Environmental Biotechnology 10(2), 2014: 60-65
It is best to use a DNA specific stain (e.g. Feulgen with a 1/4 strength Fast or Pale Green counterstain. Feulgen is easy, immerse fixed slides in 5M HCl for 30 mins, rinse in tap water then immerse in Schiff's Reagent for 2 hours before rinsing in tap water.
Article The HUman MicroNucleus project on eXfoLiated buccal cells (H...
I am not sure whether it can be of help for your specific micronucleus test from buccal mucosa, but here is a detailed protocol-video for cytokinesis Block micronucleus assay performed on lymphocytes:
https://www.youtube.com/watch?v=gc5uyTyHTrU
Hope it helps you clarify at least certain steps of the assay!