Triglyceride Assay from Cells and Tissues
From Bridges Lab Protocols
- 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)
- 10M KOH
- 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)
- 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 400 ul of the bottom layer into a new tube
- 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 560ul (80ul) of glycerol reagent and 140ul (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.