Center for Biomarker Research in Medicine (CBMed)
A sustainable alternative to deep-freezing for Plasma preservation.
Plasma is a complex biological fluid with a high protein content and significant clinical relevance. It is particularly sensitive to freeze-thaw cycles and storage conditions, which can affect the stability of its components and compromise downstream analyses. The extensive use of ULT freezers is increasingly incompatible with the growing demands related to costs, energy consumption, space, and safety in biological sample collections. Therefore, there is an urgent need for an alternative stabilization method that mitigates these risks while maintaining the benefits of cryopreservation, such as flexibility for downstream applications
Objective
To compare the quality and functionality of plasma samples stabilized and stored at room temperature versus those frozen at -80°C, within the context of a prospective sample collection. Lyophilized samples are compared with frozen samples based on the defined quality criteria, with the aim of demonstrating their usefulness in studying different plasma/serum metabolites.
Materials and Methods
Samples used for the study
Plasma and serum samples
20 samples
10 samples from cirrhosis patients an 10 samples frotm healthy volunteers
Procedure
After plasma extraction, each sample will be divided into eight 500 µL aliquots: four will undergo lyophilization and four will be stored at -80 °C to serve as controls. Both processes will be performed within four hours of extraction to ensure sample integrity. Each condition provides enough material for evaluation at a minimum of two timepoints.
For each sample, quality assessment will be performed in 2 storage conditions (-80ºC and RT) at 3 different timepoints: After 1, 6 and 12 months from storage at -80ºC or RT. Initial conditions of the sample before storage will be also evaluated for the techniques available for single measurements.
Quality Assurance
ELISA
The Quality assessment will consist of:
- ELISA:
- Diamine oxidase (serum)
- FGF21 (LiHep Plasma)
- LBP (EDTA Plasma)
Routine Biochemistry: parameters for liver and renal function, as well as a selection for hormone and enzyme
measurements. Variability of the techniques will be considered when analyzing the results based on the data published by the vendors. For FG21 analysis, duplicate measurements will be performed due to the limited information available on the variability of this test. These tests have been chosen based on previous experience of the group analyzing theses markers in these types of samples.
Results
Coming soon…
Conclusion
Coming soon…
