Effect of storage time, temperature, antioxidant and thawing on fatty acid composition of plasma, serum and red blood cells - A pilot biobank study.

BACKGROUND: It studies on the factors that affect the stability of fatty acid profiles from human blood specimens are generally performed by evaluating the effect of a single factor on an individual fatty acid and excluding a considerable amount of data from the total fatty acid profiles.

METHODS: The stability of fatty acids from plasma, serum and red blood cells (RBC) was evaluated in terms of time, temperature, antioxidant and thawing. The fatty acids were methylated and analyzed by gas chromatography. The large volume of data is evaluated simultaneously and automatically by observing an Excel-based colour scale that indicates whether the fatty acid profiles have changed significantly as a result of the storage time (0-52weeks), temperature (-20°C/-80°C), butylated hydroxytoluene (BHT) antioxidant (presence/absence) or thawing (single/multiple).

RESULTS: Fatty acids from plasma were stable at both temperatures (-20°C/-80°C) regardless of BHT. Fatty acids from serum without BHT degrades faster at -80°C than -20°C and fatty acids from RBC without BHT degrades faster at -20°C than -80°C. Addition of BHT inhibits this effect in serum and RBC. Multiple thawing of RBC without BHT demonstrated that polyunsaturated fatty acids were generally more susceptible for changes at -80°C than at -20°C while BHT prevents partially this effect.

CONCLUSIONS: This study draws attention to the importance of pre-analytical considerations when storing blood samples in biobanks and the need of careful judgments when analyzing fatty acids profiles.