Subcellular fractionation protocol
Procedure for separating nuclear, membrane and cytoplasmic cell fractions using centrifugation methods.
Procedure
- All centrifugations should be done at 4°C. Samples should be kept on ice throughout the procedure.
- Transfer cells from 10 cm plates into 500 μL fractionation buffer, eg by scraping. Incubate 15 min on ice.
- Using 1 mL syringe pass cells suspension through a 27 gauge needle 10 times (or until all cells are lysed).
- Leave on ice for 20 min.
- Centrifuge sample at 720 x g (3,000 rpm) for 5 min. Pellet contains nuclei. Supernatant contains cytoplasm, membrane and mitochondria.
- Transfer supernatant into a fresh tube and keep on ice. This will be dealt with in steps 9-13.
- Wash nuclear pellet remained after step 6 with 500 μL of fractionation buffer. Disperse the pellet with a pipette and pass through a 25 gauge needle 10 times. Centrifuge again at 3,000 rpm for 10 min. Discard the supernatant and keep the pellet that contains nuclei.
- Resuspend the pellet from step#7 in TBS with 0.1% SDS. Sonicate the suspension briefly to shear genomic DNA and homogenise the lysatae (3 sec on ice at a power setting of 2-continuous).
- Continue with cytoplasm, membrane and mitochondria fraction from step 6.
- Centrifuge supernatant recovered in step #6 at 8,000 rpm (10,000 x g) for 5 min. Pellet contains mitochondria. Supernatant contains cytoplasm and membrane.
- Transfer supernatant from step 10 into a fresh tube and keep on ice. This is the cytoplasm and membrane fraction.
- Process the mitochondia pellet from step 11, as described for the nuclear pellet in step 7, to obtain mitochondrial lysate in TBS/0.1% SDS.
- For a membrane fraction, centrifuge the supernatant from step 11 in an ultracentrifuge at 40,000 rpm (100,000 x g) for 1 h. Wash pellet by adding 400 μL of fractionation buffer. Resuspend by pipetting and pass through a 25 G needle. Re-centrifuge for 45 min. Resuspend the membrane pellet in the same buffer as used for the nuclei.
- Optional: Concentrate the supernatant by centrifuging through the filter unit. This concentrates the cytosol down to approximately 50–75 μL.
Subcellular fractionation buffer
| MW
| mM
| Add per L
|
HEPES (pH 7.4)
| 238.30
| 20
| 4.77
|
KCl
| 74.55
| 10
| 0.75
|
MgCl2
| 95.21
| 2
| 0.14
|
EDTA
| 292.24
| 1
| 0.29
|
EGTA
| 380.35
| 1
| 0.38
|
Just before use, add the following per 10 mL:
| Stocks
| Per 50 ml
|
1mM DTT
| 1M
| 10 μL
|
PI Cocktail (III)
| -
| 50 μL
|
#Abcam #다윈바이오 #DAWINBIO #Subcellular #Fractionation #Subcellular fractionation #프로토콜 #Protocol
Subcellular fractionation protocol
Procedure for separating nuclear, membrane and cytoplasmic cell fractions using centrifugation methods.
Procedure
Subcellular fractionation buffer
Just before use, add the following per 10 mL:
#Abcam #다윈바이오 #DAWINBIO #Subcellular #Fractionation #Subcellular fractionation #프로토콜 #Protocol