INFLUENCE OF TEMPERATURE ON LONG-TERM KERATIN IMMUNOREACTIVITY FOR ORAL EXFOLIATIVE

We previously showed that keratin profiles can be of value in the diag nosis of oval cancer when using exfoliative cytology. In the future, t hey may form part of a screening program for oral cancer. This study e valuated the influence of long-term storage on keratin expression. Sme ars were collected from the clinically normal buccal mucosa and dorsal tongue of 22 patients. Half were stored in a refrigerator (5 degrees C) and half in a freezer (-70 degrees C). A fetal of 528 smears were c ollected. A panel of three antikeratin antibodies (LP34, AE8 and 1C7) wits used to identify the preservation of keratin expression (graded a s absent, few cells positive or many cells positive). The results for smears from dorsal tongue indicated that many cells were impermeable b y the antikeratin antibodies. However, a satisfactory level of keratin immunoreactivity teas observed in smears from buccal mucosa stored at -70 degrees C for over one year. Results for storage at 5 degrees C f or both sites were inadequate after one month. Thus, smears from nonke ratinized oral sites may be stored at -70 degrees C for at least one y ear without a profound loss of keratin immunoreactivity, thus allowing examination of archival material.