The Liquid-Liquid extraction of Lipid

by Folch method

By: Raghdah malibari

Supervisor: Dr. Fotoon Sayegh + Prof. George Agglis

LIPID, are a large and diverse group

of naturally occurring organiccompounds. Relatively insoluble in waterand soluble in nonpolar solvents such asether and chloroform. Found as structuralcomponents of cell membranes.

Functions of lipids, Storage

form of energy, Structural components ofbiomembranes, Nonpolar lipids act aselectrical insulators, Provide shape andcontour to the body, Act as metabolicregulators.

Raghdah Malibari, 2013

Raghdah Malibari, 2013

1) The tissue is homogenized with chloroform/methanol (2/1) to a finalvolume 20 times the volume of the tissue sample (1 g in 20 ml ofsolvent mixture). After dispersion, the whole mixture is agitated during15-20 min in an orbital shaker at room temperature.

2) The homogenate is either filtrated (funnel with a folded filter paper) orcentrifuged to recover the liquid phase.

3) The solvent is washed with 0.2 volume (4 ml for 20 ml) of water orbetter 0.9% NaCl solution. After overtaxing some seconds, the mixtureis centrifuged at low speed (2000 rpm) to separate the two phases.

4) Remove the upper phase by siphoning and kept it to analyzegangliosides or small organic polar molecules. If necessary (need ofremoving labelled molecules...), rinse the interface one or two timeswith methanol/water (1/1) without mixing the whole preparation.

5) After centrifugation and siphoning of the upper phase, the lowerchloroform phase containing lipids is evaporated under vacuum in arotary evaporator or under a nitrogen stream if the volume is under 2-3ml.

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Raghdah Malibari, 2013

The lipid extraction by Folch methodHomogenized by using 2:1

chloroform/methanol mixture

Filltration by (fillter paper or centrifuge)

Washing with (water or NaCl solution)

The mixture is centrifuge

Remove the upper phase (Methanol) by siphoning

The lower phase (Chloroform)

Result: LIPIDS

Raghdah Malibari, 2013