Homogenization Buffer (50 mM Tris pH 8, 5 mM EDTA, 30 mM Mannitol, PI inhibitor, can be made in bulk without the PI, PI added fresh) (to make 50 mL of homogenization buffer - 2.5 mL of 1M Tris pH 8, 500 uL of 0.5 M EDTA, 0.273 g Mannitol, fill up the rest with water)
10M KOH (28.1g in 50 mL of water)
Chloroform/Methanol Mixture (2:1)
Butanol Mixture: 3 mL butanol, 1.66 mL Triton-X114, 0.33 mL Methanol
Sigma Triglyceride Assay Kit (Cat TR0100)
Protocol
Weigh out 30-50mg tissue (record weights for normalization) on dry ice into round bottom eppendorf tube (2 mL). Add one stainless steel ball bearing.
Add 500ul Homogenization Buffer
Homogenize with Qiagen Tissue Lyser for 3 minutes @ 25Hz for Liver/WAT or for 5 minutes @ 30Hz for muscle
Add 12.5ul KOH
Mix by inverting then transfewr sample to a new 1.5 mL tube. Place dirty ball bearing in ethanol (located in the fume hood)
Add 800ul Chloroform/Methanol Mixture
Vortex vigorously then sit at room temperature for 5 minutes
Centrifuge for 10 minutes @ 13000G
Transfer 200 ul of the bottom layer into a new tube
Centrifuge again for 7-10 minutes @ 13000G
Transfer 150 ul of the bottom layer into the new tube (if there is enough of the bottom layer, transfer a total of 200 ul)
Let evaporate overnight at room temperature
Add(50ul) of Butanol Mixture and vortex. See Suggested Volumes for your specific tissue.
Measure triglyceride levels using SIgma Diagnostic Kit, using 5ul of sample.
Resuspend triglyceride and glycerol reagent with water if necessary
Calculate how many sample you have (samples + blank + standard curve)
Prepare reagent. You need 80uL of glycerol reagent and 20uL of triglyceride reagent. Make extra and combine in a Falcon tube.
Aliquot 100ul into a well of a 96 well plate
For standards, add 0-5 and .5ul of glycerol standard
Add 5ul of resuspended lipid to each well to start (also make a 5ul blank of the butanol mixture) and mix.
Pop any bubbles with tip before incubating.
Let sit for ~30 mins @ room temperature (or 5mins @ 37C if you are in a hurry). If using >10ul of butanol mix the solution may be cloudy. Let it settle and it should become more clear.
Measure absorbance @ 540nm
If any samples are A540<0.1 or above the 5ul standard the A540, then repeat with more or less lipid as required.