Assessment of the Stability of Hepatobiliary Disease Biomarkers under Varying Storage Conditions

ABSTRACT

A common problem in clinical laboratories is maintaining the stability of analytes during sample storage, destined for batch analysis. Factors such as equipment breakdown, lack of reagents, electricity outages can cause losses/deterioration in specimens collected and thus the samples will need storage. This study was designed to assess the stability in blood of hepatobiliary disease biomarkers (alanine amino transferase (ALT), aspartate amino transferase (AST), gamma glutamyl transferase (γ-GT), alkaline phosphatase (ALP) and albumin (ALB)) under varying storage conditions. Thirty study participants (five males and twenty-five females) were recruited from the Buea Regional Hospital and the Muea Sub-divisional Hospital. Serum samples from these participants was used to measure the biomarker levels using spectrophotometric commercial assay kits. Each biomarker’s activity/concentration was measured over the course of thirty days in samples collected and preserved at 25, 4, -20 and -86 °C with/without the use of glycerol. The concentration/activities of AST, ALP and ALB measured remained stable at -20 °C for up to 14 days as well as at -86 °C for up to 30 days in samples that were stored without glycerol. AST was stable at 4 °C for up to 3 days in the samples stored with glycerol. Albumin equally was stable at -86 °C for up to 30 days in the samples stored with glycerol. Based on this study’s findings, it is recommended that: Same day analysis be done for the measurement of ALT, γ-GT. ALP can be stored at 4 °C for short periods such as 3 days. Albumin and AST can be stored for up to 14 and 30 days when stored at -20 °C and -86 °C respectively, and is suitable for research purposes.