Stability of retinol binding protein after 36 months’ storage at -20⁰C
Retinol is a common indicator of vitamin A status. Retinol forms a complex with retinol binding protein (RBP) at a ratio of 1:1 and is thus transported in the serum. RBP is easily measured in serum to provide information on retinol and vitamin A concentrations. Retrospective or small-scale clinical research studies may store serum samples for long durations prior to RBP analysis. The aim of this study was to evaluate the stability of RBP concentrations during prolonged storage at -20⁰C.