METHYLATION OF FATTY ACIDS (KROPINSKI
METHOD)
OBJECTIVE : To methylate fatty acids in whole cells
or lipopolysaccharide.
REAGENTS :
Methanol-Hydrochloride Reagent Kit
10mg of whole cells or 1 mg of lipopolysaccharide
400 nmoles of fatty acid standard (pentadecanoic acids
C15)
METHODS :
-
Prepare 1M MeOH-HCl reagent according to the instruction
given with the kit.
-
Add internal standard (C15 fatty acid) to give a final concentration
of 400 nmoles/100ml (usually 10mg of C15 in 100ml of reagent.
-
Weigh 10mg of whole cells or 1 mg of LPS into a clean screw-cap
tube.
-
Add 1ml of MeOH-HCl reagent/internal standard into each tube
and vortex.
-
Heat at 100oC for 20 minutes. (Note: each tube
should be very well sealed with teflon tape and grease to prevent evaporation.)
-
Sonicate and heat at 100oC overnight.
-
Neutralize acidity with 0.5N NaOH. Test pH with pH paper.
-
Centrifuge in clinical centrifuge for 5 minutes. Save supernatent
in clean glass vial.
-
Do gas chomatography with programmed REWH method.
Updated 01 December 2000.