Abstract
Background: In epidemiological research it is very important to test the stability of biomarkers as a function of both storage time and temperature. In this study the stability of both folate and vitamin B12 in human serum samples have been tested after storage at three different temperatures up to 1 year.
Methods: Serum samples of 16 individuals were used in this study. The concentration of folate and vitamin B12 has been determined at T=0 and at several time points up to 1 year after storage at –20°C, –70°C and –196°C. The statistical difference from the initial value at T=0 were determined with a t-test.
Results: Folate in serum samples remained stable at –70°C but was not stable during storage at –20°C. A fast decrease was observed after Day 4 which resulted in a stable level of about 60% of the original value measured at T=0 (p<0.001). The rank order of folate concentration in the samples, however, was not affected. The stability of vitamin B12 was good at all temperatures tested.
Conclusions: Measurements of folate concentrations in serum stored at –20°C are not reliable. The rank order, however, was not changed. Vitamin B12 was stable at all temperatures tested. For both folate and vitamin B12 storage at –70°C is sufficient to maintain the original concentration for 1 year. Storage at –196°C in liquid nitrogen is not necessary for these nutrients.
©2012 by Walter de Gruyter Berlin Boston
Artikel in diesem Heft
- Masthead
- Masthead
- Editorials
- Cancer epigenomics: moving slowly, but at a steady pace from laboratory bench to clinical practice
- Laboratory networking and sample quality: a still relevant issue for patient safety
- Reviews
- DNA methylation biomarkers and their utility for solid cancer diagnostics
- DNA methylation biomarkers in biological fluids for early detection of respiratory tract cancer
- Global DNA hypomethylation in cancer: review of validated methods and clinical significance
- Genetics and Molecular Diagnostics
- δ0-Thalassemia in cis of βKnossos globin gene: first homozygous description in thalassemia intermedia Libyans and first combination with codon 39 (C→T) in thalassemia intermedia Tunisian patients
- Genetic-based reference values for angiotensin-converting enzyme (ACE) according to I/D polymorphism in a Spanish population sample
- General Clinical Chemistry and Laboratory Medicine
- Effects of sample transportation on commonly requested laboratory tests
- Long-term (in)stability of folate and vitamin B12 in human serum
- Information comparison of the effects of drugs on laboratory tests in drug labels and Young’s book
- First evaluation of Capillarys 2 Flex Piercing® (Sebia) as a new analyzer for HbA1c assay by capillary electrophoresis
- Antioxidant and oligonutrient status, distribution of amino acids, muscle damage, inflammation, and evaluation of renal function in elite rugby players
- Validation of the body fluid module on the new Sysmex XN-1000 for counting blood cells in cerebrospinal fluid and other body fluids
- Measuring Rivaroxaban in a clinical laboratory setting, using common coagulation assays, Xa inhibition and thrombin generation
- Cancer Diagnostics
- Increased concentrations of growth factors and activation of the EGFR system in breast cancer
- Infectious Diseases
- Incidence and significance of elevated lactate in the identification of critically ill patients
- Cardiovascular Diseases
- Lipoprotein-associated phospholipase A2 is elevated in patients with severe aortic valve stenosis without clinically overt atherosclerosis
- Diabetes
- Serum cystatin C as a marker for early detection of chronic kidney disease and grade 2 nephropathy in Japanese patients with type 2 diabetes
- Letters to the Editor
- Establishing professional phlebotomist group for quality control of the preanalytic variables of clinical laboratory
- Application of quality specification based on biological variation in planning quality control strategy
- Analytical and clinical evaluation of a new immunoassay for therapeutic drug monitoring of infliximab and adalimumab
- Comparison of relationships between FT4 and log TSH in Access DXI 800 Unicel, Modular E170 and ADVIA Centaur XP Analyzer
- Assay-specific pitfalls of catecholamine HPLC assays
- Evaluation of automated nucleated red blood cells counting on Sysmex XE5000 and Siemens ADVIA 2120
- Evaluation of the immature myeloid information (IMI) by Sysmex XE 2100® hematology analyzer in the identification of blasts of myeloid lineage
- Congress Abstracts
- Congress of Laboratory Medicine and Clinical Chemistry / 4th Annual Meeting of the Austrian Society for Laboratory Medicine and Clinical Chemistry (ÖGLMKC)
- Abstracts of the 2012 Convocation of Experts on Laboratory Quality / Embracing the Need of Continued Vigilance to Assure Quality Outcomes in the Modern Laboratory
Artikel in diesem Heft
- Masthead
- Masthead
- Editorials
- Cancer epigenomics: moving slowly, but at a steady pace from laboratory bench to clinical practice
- Laboratory networking and sample quality: a still relevant issue for patient safety
- Reviews
- DNA methylation biomarkers and their utility for solid cancer diagnostics
- DNA methylation biomarkers in biological fluids for early detection of respiratory tract cancer
- Global DNA hypomethylation in cancer: review of validated methods and clinical significance
- Genetics and Molecular Diagnostics
- δ0-Thalassemia in cis of βKnossos globin gene: first homozygous description in thalassemia intermedia Libyans and first combination with codon 39 (C→T) in thalassemia intermedia Tunisian patients
- Genetic-based reference values for angiotensin-converting enzyme (ACE) according to I/D polymorphism in a Spanish population sample
- General Clinical Chemistry and Laboratory Medicine
- Effects of sample transportation on commonly requested laboratory tests
- Long-term (in)stability of folate and vitamin B12 in human serum
- Information comparison of the effects of drugs on laboratory tests in drug labels and Young’s book
- First evaluation of Capillarys 2 Flex Piercing® (Sebia) as a new analyzer for HbA1c assay by capillary electrophoresis
- Antioxidant and oligonutrient status, distribution of amino acids, muscle damage, inflammation, and evaluation of renal function in elite rugby players
- Validation of the body fluid module on the new Sysmex XN-1000 for counting blood cells in cerebrospinal fluid and other body fluids
- Measuring Rivaroxaban in a clinical laboratory setting, using common coagulation assays, Xa inhibition and thrombin generation
- Cancer Diagnostics
- Increased concentrations of growth factors and activation of the EGFR system in breast cancer
- Infectious Diseases
- Incidence and significance of elevated lactate in the identification of critically ill patients
- Cardiovascular Diseases
- Lipoprotein-associated phospholipase A2 is elevated in patients with severe aortic valve stenosis without clinically overt atherosclerosis
- Diabetes
- Serum cystatin C as a marker for early detection of chronic kidney disease and grade 2 nephropathy in Japanese patients with type 2 diabetes
- Letters to the Editor
- Establishing professional phlebotomist group for quality control of the preanalytic variables of clinical laboratory
- Application of quality specification based on biological variation in planning quality control strategy
- Analytical and clinical evaluation of a new immunoassay for therapeutic drug monitoring of infliximab and adalimumab
- Comparison of relationships between FT4 and log TSH in Access DXI 800 Unicel, Modular E170 and ADVIA Centaur XP Analyzer
- Assay-specific pitfalls of catecholamine HPLC assays
- Evaluation of automated nucleated red blood cells counting on Sysmex XE5000 and Siemens ADVIA 2120
- Evaluation of the immature myeloid information (IMI) by Sysmex XE 2100® hematology analyzer in the identification of blasts of myeloid lineage
- Congress Abstracts
- Congress of Laboratory Medicine and Clinical Chemistry / 4th Annual Meeting of the Austrian Society for Laboratory Medicine and Clinical Chemistry (ÖGLMKC)
- Abstracts of the 2012 Convocation of Experts on Laboratory Quality / Embracing the Need of Continued Vigilance to Assure Quality Outcomes in the Modern Laboratory