The effects of a single freeze-thaw cycle on concentrations of nutritional, noncommunicable disease, and inflammatory biomarkers in serum samples
Background: The stability of biological samples is vital for reliable measurements of biomarkers in large-scale survey settings, which may be affected by freeze-thaw procedures. We examined the effect of a single freeze-thaw cycle on 13 nutritional, noncommunicable diseases (NCD), and inflammatory bioanalytes in serum samples. Method: Blood samples were collected from 70 subjects centrifuged after 30 minutes and aliquoted immediately. After a baseline analysis of the analytes, the samples were stored at − 70°C for 1 month and reanalyzed for all the parameters. Mean percentage differences between baseline (fresh blood) and freeze-thaw concentrations were calculated using paired sample t-tests and evaluated according to total allowable error (TEa) limits (desirable bias). Results: Freeze-thaw concentrations differed significantly (p < 0.05) from baseline concentrations for soluble transferrin receptor (sTfR) (− 5.49%), vitamin D (− 12.51%), vitamin B12 (− 3.74%), plasma glucose (1.93%), C-reactive protein (CRP) (3.45%), high-density lipoprotein (HDL) (7.98%), and cholesterol (9.76%), but they were within respective TEa limits. Low-density lipoprotein (LDL) (− 0.67%), creatinine (0.94%), albumin (0.87%), total protein (1.00%), ferritin (− 0.58%), and triglycerides (TAG) (2.82%) concentrations remained stable following the freeze-thaw cycle. In conclusion, single freeze-thaw cycle of the biomarkers in serum/plasma samples after storage at − 70°C for 1 month had minimal effect on stability of the studied analytes, and the changes in concentration were within acceptable limit for all analytes.
Abraham, Ransi, Garima Rana, Praween Kumar Agrawal, Robert Johnston, Avina Sarna, Sowmya Ramesh, Rajib Acharya, Nizamuddin Khan, Akash Porwal, Sucheta Banerjee Kurundkar, Arvind Pandey, Raghu Pullakhandam, K. Madhavan Nair, Geeta Trilok Kumar, Harshpal Singh Sachdev, Umesh Kapil, Sila Deb, Arjan De Wagt, Ajay Khera, and Lakshmy Ramakrishnan. 2021. "The effects of a single freeze-thaw cycle on concentrations of nutritional, noncommunicable disease, and inflammatory biomarkers in serum samples," Journal of Laboratory Physicians 13(1): 6–13.
India Comprehensive National Nutrition Survey