Lipid Analysis

We are mostly focussing on the analysis of algal and plant glycerolipids and their precursors. Glycerolipids are divided into membrane lipids (phospholipids, galactolipids) and storage lipids (triacylglycerols).

The isolation of glycerolipids is usually performed by chloroform-methanol extraction followed by several washing steps or solid phase extraction. Depending on the scientific question about lipid quality and/or quantity we use the following techniques:

Thin layer chromatography (fatty acids, fat alcohols, glycerolipids)
This cheap and fast method is used for separation of different lipid classes and allows the analysis of radio-labeled metabolites.

Gas chromatography-mass spectrometry (fatty acids, fat alcohols) (Agilent 7890A)
Membrane lipids are comprised of a glycerol backbone and one, two or three fatty acids. To determine total fatty acid compositions, we transmethylate lipid extracts and analyse them by gas chromatography-mass spectrometry. This analysis provide informations about chain length, saturation degree, position(s) of the double bond(s), and the amount of each fatty acid methyl ester.

Direct infusion tandem mass spectrometry (quality and quantity of glycerolipid classes and species) ((6420, Agilent)
Instead of column separation, the total lipid extracts are directly infused into a mass spectrometer. By using different scan modes, we are able to analyse the fatty acid composition of each membrane lipid class. This analysis provides detailed informations about several hundred lipid molecular species of the respective lipid class within a few minutes.

Data analysis
Qualitative analysis is performed on standard compounds and different databases.
Quantitative analysis of raw data is mostly calculated by using R! as software environment.