The document describes the Folch method for extracting lipids. It involves homogenizing tissue in a 2:1 chloroform/methanol mixture. The homogenate is then filtered or centrifuged to separate the liquid phase. This phase is washed with water or saline solution and centrifuged to separate the mixture into upper and lower phases. The upper methanol phase is removed by siphoning and contains polar molecules. The lower chloroform phase contains lipids and is evaporated, leaving only lipids.

1. The Liquid-Liquid extraction of
Lipid
by Folch method
By: Raghdah malibari
Supervisor: Dr. Fotoon Sayegh + Prof.
George Agglis

2. LIPID,
are a large and diverse group
of
naturally
occurring
organic
compounds. Relatively insoluble in water
and soluble in nonpolar solvents such as
ether and chloroform. Found as structural
components of cell membranes.
Functions of lipids, Storage
form of energy, Structural components of
biomembranes, Nonpolar lipids act as
electrical insulators, Provide shape and
contour to the body, Act as metabolic
regulators.
Raghdah Malibari, 2013

3. Raghdah Malibari, 2013

4. 2) The homogenate is either filtrated (funnel with a folded filter paper) or
centrifuged to recover the liquid phase.
3) The solvent is washed with 0.2 volume (4 ml for 20 ml) of water or
better 0.9% NaCl solution. After overtaxing some seconds, the mixture
is centrifuged at low speed (2000 rpm) to separate the two phases.
4) Remove the upper phase by siphoning and kept it to analyze
gangliosides or small organic polar molecules. If necessary (need of
removing labelled molecules...), rinse the interface one or two times
with methanol/water (1/1) without mixing the whole preparation.
5) After centrifugation and siphoning of the upper phase, the lower
chloroform phase containing lipids is evaporated under vacuum in a
rotary evaporator or under a nitrogen stream if the volume is under 2-3
Raghdah Malibari, 2013
ml.
Folch Method (1957)
1) The tissue is homogenized with chloroform/methanol (2/1) to a final
volume 20 times the volume of the tissue sample (1 g in 20 ml of
solvent mixture). After dispersion, the whole mixture is agitated during
15-20 min in an orbital shaker at room temperature.

5. The lipid extraction by Folch method
Homogenized 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