PURPOSE: To assess the viability of cultured epithelium and preserved by 
freezing for periods varying from one month to one year.
METHODS: Samples of cultured epithelium were incubated in cryoprotectant medium 
(Group A), packed in aluminum envelopes and packed in polystyrene boxes. The 
boxes were subjected to a temperature of-70 ºC. After freezing for a period of 
time ranging from one to 12 months, cultured epithelial samples were assessed 
for their viability by vital staining (Trypan blue) and metabolic analysis based 
on glucose consumption and lactate production. Samples of not frozen cultured 
epithelium (Group B) were also tested for viability and the results obtained 
were used as comparison parameter for the variation of viability.
RESULTS: Statistical analysis between the group A and B indicate that the mean 
age of the donors (p=0.51) and the culture time (p=1.18) showed no statistical 
difference. In 30 days we obtained 37% of the original viability of cultured 
epithelium, 25% at six months and one year, less than 15%. This trend was 
confirmed statistically with a reduction of approximately 1.8% of the original 
viability epithelium cultured every 30 days of storage. In the analysis by 
lactate production, similar results were observed. In the analysis by the 
glucose consumption results were not significant. The viability indices show 
statistically significant difference between the group A and B (p<0.0001).
CONCLUSIONS: Although cryopreserved cultured epithelium showed significant 
reduction of viability, all samples remained viable. It was also found that the 
viability of cryopreserved cultured epithelial decreased as a function of 
storage time.