The influence of storage time and temperature on G-6PD enzyme activity for the enzymatic colorimetric measurement

Resumen

Background: To ensure accurate results when measuring glucose-6-phosphate dehydrogenase (G-6PD) enzyme activity, it is essential to take care of pre-analytical aspects related to time and storage conditions. This study sought to identify the ideal conditions for measuring G-6PD activity on filter paper using a colorimetric enzymatic method. Methods: The biological material was collected from 17 individuals deficient in G-6PD enzyme activity and 19 with normal enzyme activity and stored in three conditions: room temperature (25.5ºC), refrigerated (5ºC), and at -20ºC. Furthermore, the G-6PD enzyme activity was evaluated daily for 15 days by the colorimetric enzymatic method. Results and Conclusion: The results revealed that 81% of the sample's enzymatic activity was explained by the linear regression model, considering temperature, the time between collection and analysis, and the individual's state of disability. At the end of the storage period, samples kept at room temperature showed significant instability, losing around 61% of enzymatic activity. This emphasizes the negative influence of temperature on G-6PD enzyme activity and highlights the importance of analyzing biological material within 48 hours. On the other hand, the samples stored under cryopreservation (-20ºC) showed greater stability, preserving more than 60% of the residual activity. This highlights the need for appropriate treatment for samples collected in locations far from the analysis laboratory. Refrigerated samples can be stored for up to seven days without affecting the classification of the individual. Finally, samples stored at -20°C proved to be the most stable option throughout the entire storage period, with no error in the individual's classification.