Table 2
Preservation of serum in freezer
Preservation
EGF (ng/ml)
Vitamin A (μg/dl)
TGF-β1 (ng/ml)
Initial day
0.61 (0.06)
52.6 (12.2)
53.9 (4.7)
1 month
0.53 (0.03)
49.1 (11.3)
53.7 (4.8)
3 months
0.53 (0.06)
48.3 (10.3)
51.4 (5.9)