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.
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.
Authors: David Kahoun; Pavla Fojtíková; František Vácha; Marie Čížková; Roman Vodička; Eva Nováková; Václav Hypša Journal: PLoS One Date: 2022-07-14 Impact factor: 3.752
Authors: Katarzyna Durda; Krzysztof Kąklewski; Satish Gupta; Michał Szydłowski; Piotr Baszuk; Katarzyna Jaworska-Bieniek; Grzegorz Sukiennicki; Katarzyna Kaczmarek; Piotr Waloszczyk; Steven Narod; Jan Lubiński; Anna Jakubowska Journal: PLoS One Date: 2017-05-11 Impact factor: 3.240
Authors: M Gołyński; K Lutnicki; W Krumrych; M Szczepanik; M Gołyńska; P Wilkołek; Ł Adamek; Ł Sitkowski; Ł Kurek Journal: J Vet Intern Med Date: 2017-08-14 Impact factor: 3.333