Does Extended Serum Sample Storage Impact Laboratory Results?

ABSTRACT Background: Prolonged storage of samples can result in changes to routine biochemical parameters. Aim: This study aimed to examine the biochemical changes in serum samples stored at –20°C for extended periods (72 hours), focusing on various routine biochemical parameters. Results: Significant changes were noted in serum glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and potassium levels after 72 hours of storage, with further deterioration observed over 3 months. The remaining parameters showed no significant alterations. Conclusion: Prolonged sample storage results in changes in analyte concentrations in serum. Serum glucose, AST, ALT, creatinine, and potassium levels should be measured within 72 hours if extended storage is necessary. All parameters should ideally be analyzed within 24 hours to prevent misinterpretation of results and ensure optimal patient care.