Pre-Analytical Stability of Glycemia and Cholesterolemia in Serum Samples After Overnight Storage Under Controlled Freezing Conditions at -20°C

The process of analysis comprised three phases: the pre-analytical, analytical, and post-analytical phases. Understanding the stability of biochemical analytes is of crucial importance. A study was conducted at the biochemistry and hematology laboratory in the National Institute of Hygiene in Rabat, Morocco. This study, that involved 160 individuals (both patients and healthy subjects), aimed to determine the stability of two biochemical parameters, glycemia and cholesterolemia in their serum. Serum samples were stored overnight at -20°C. During the study, blood samples were collected from fasting volunteers using plain serum tubes. Simultaneously, a questionnaire was completed to assess the subject's health status. Upon arrival at the laboratory, the collection tubes were sorted and then centrifuged to obtain the serum, which was subsequently analyzed using the Cobas C311 system. After that, they were stored overnight at a temperature of -20°C and reanalyzed the following day. Statistical tests showed that blood glucose and cholesterolemia remained stable after being frozen and stored overnight at -20°C. This study concluded that glycemia and cholesterolemia maintain their stability under the chosen conditions.