Staining of micronuclei in squamous epithelial cells of human oral mucosa.
OBJECTIVE
To evaluate the influence of methodologic variables, staining method and sampling, on the frequency of micronuclei scored in squamous epithelial cells of oral mucosa. Micronuclei were used as biomarkers of structural and numerical chromosome damage.


METHODS
Feulgen and Giemsa stain and fluorescent dyes Hoechst 33258 and propidium iodide were used for micronucleus staining. Cells were collected by either light or vigorous scraping of oral mucosa.


RESULTS
Staining of micronuclei by Hoechst 33258 proved more handly, less time consuming and at least equally reliable to the more widely used Feulgen staining. Results with Giemsa stain and propidium iodide were unsatisfactory. Micronuclei were less frequent in superficial layers of the oral mucosa.


CONCLUSIONS
Hoechst 33258 can be recommended for micronucleus staining in squamous epithelial cells of oral mucosa. Differences in scraping may affect the measurement of micronucleus frequency; scraping should therefore be carefully standardized in each laboratory.
Casartelli
G
G
Environmental Tumours Center-Mutagenesis Laboratory, National Institute for Research on Cancer, Genoa, Italy.
Monteghirfo
S
S
De Ferrari
M
M
Bonatti
S
S
Scala
M
M
Toma
S
S
Margarino
G
G
Abbondandolo
A
A
D004847:Epithelial Cells / Q000166:cytology; D006801:Humans; D048629:Micronuclei, Chromosome-Defective; D009061:Mouth Mucosa / Q000166:cytology*; D013194:Staining and Labeling / Q000379:methods*