Figure 1

Stability of serum 3-BrY concentration for each storage temperature. When compared to fresh samples, 3-BrY concentrations were stable at 4°C for up to 7 days (%CV ≤ 8.5, P > 0.05), at −20 up to 30 days (%CV ≤ 15.8, P > 0.05 ), and at −80°C up to 180 days (%CV ≤ 9.9, P > 0.05). However, 3-BrY concentrations were not stable at −20°C at 60 days (%CV ≤ 30.3, P = 0.0018).