Freezers in research institutions often contain a plethora of samples left over from studies performed years or even decades ago. Along with samples stored in biobanks, these could prove to be treasure troves for metabonomic research. Although the influence of sample handling and short to medium term storage on conventionally determined blood parameters has been reported, little is known about the effects of long term storage (years to decades) on plasma samples. The aim of this study was to investigate the influence of long term storage on the metabolite profile and to assess the value of archived samples for metabonomic studies. Heparinised plasma of 22 heifers that had been stored at -20 °C for between 2 and 15 years was analysed using NMR spectroscopy and statistical analysis techniques. Lactate (principal component 1) explained 79.6 % of variance between all spectra, but was not correlated with storage time. The highest correlation with storage time (R 2 = 0.474) was found for betaine, with other metabolites (acetoacetate, histidines, glycerol, lipids and glucose) also showing moderate correlation (R 2 values between 0.217 and 0.437). Our results indicate that samples stored for extended periods of time can potentially be used in metabonomics studies, if precautions are taken during data analysis.
- Metabolite stability
- Principal component analysis
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Clinical Biochemistry