The effect of freeze/thaw cycles on reproducibility of metabolic profiling of marine microalgal extracts using direct infusion high-resolution mass spectrometry (HR-MS)

Hans Chr Eilertsen; Siv Huseby; Maria Degerlund; Gunilla K Eriksen; Richard A Ingebrigtsen; Espen Hansen

doi:10.3390/molecules191016373

The effect of freeze/thaw cycles on reproducibility of metabolic profiling of marine microalgal extracts using direct infusion high-resolution mass spectrometry (HR-MS)

Molecules. 2014 Oct 13;19(10):16373-80. doi: 10.3390/molecules191016373.

Authors

Hans Chr Eilertsen¹, Siv Huseby², Maria Degerlund³, Gunilla K Eriksen⁴, Richard A Ingebrigtsen⁵, Espen Hansen⁶

Affiliations

¹ Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø N-9037, Norway. hans.c.eilertsen@uit.no.
² MabCent-SFI, UiT The Arctic University of Norway, Tromsø N-9037, Norway. siv.huseby@uit.no.
³ Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø N-9037, Norway. maria.degerlund@uit.no.
⁴ Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø N-9037, Norway. gunilla.eriksen@uit.no.
⁵ Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, Tromsø N-9037, Norway. richard.a.ingebrigtsen@uit.no.
⁶ Marbio, UiT The Arctic University of Norway, Tromsø N-9037, Norway. espen.hansen@uit.no.

Abstract

During normal sample preparation, storage in freezers and subsequent freeze/thaw cycles are commonly introduced. The effect of freeze/thaw cycles on the metabolic profiling of microalgal extracts using HR-MS was investigated. Methanolic extracts of monocultures of Arctic marine diatoms were analyzed immediately after extraction, after seven days of storage at -78 °C (one freeze/thaw cycle), and after additional seven days at -20 °C (two freeze/thaw cycles). Repeated direct infusion high-resolution mass spectrometry analysis of microalgae extracts of the same sample showed that reproducibility was ca. 90% when a fresh (unfrozen) sample was analyzed. The overall reproducibility decreased further by ca. 10% after the first freeze/thaw-cycle, and after one more freeze/thaw cycle the reproducibility decreased further by ca. 7%. The decrease in reproducibility after freeze-thaw cycles could be attributed to sample degradation and not to instrument variability.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acclimatization
Diatoms / physiology*
Mass Spectrometry / methods*
Metabolomics / methods*
Methanol / metabolism
Microalgae / physiology
Reproducibility of Results

Substances

Methanol