The effect of sample storage on the reliability of thyroglobulin and thyroglobulin-antibody measurements

ObjectivesTo investigate how sample-storage alters thyroglobulin (Tg) and thyroglobulin-antibody (TgAb) immunoreactivity.Design and methodsTg and TgAb measurements at different storage-times and -temperatures.Results48-h-storage at 4–10 °C (but not 8 h at room temperature) increased Tg and decreased TgAb immunoreactivity by maximum + 23% and − 16%. 4-weeks-storage at − 17 to − 20 °C decreased both Tg and TgAb by max. 21–31%.ConclusionsStorage of samples at 4–10 °C for > 24–48 h, or at − 17 to − 20 °C for > 2–3 weeks significantly alters Tg and TgAb immunoreactivity.