I'm already extracting total protein with RIPA buffer. I now want to extract proteins only from the nucleus and only from the cytosol. The proteins shall be used for Western Blotting.
I'm attaching a paper that has a protocol for isolation of nuclei from human HeLa cells. If you follow this protocol, the first supernantant from the nuclear recovery step (1st low g centrifugation) would consistute the cytoplasmic subcellular fraction. Dialyze against an appropriate buffer and use this fraction for assessment of cytoplasmic proteins. Carry out the remainder of the nuclear extraction procedure to recover protein from the nuclear subcellular fraction. you can determine the efficiency of the fractionation by blotting for compartment specific proteins (i.e., a DNA polymerase of your choice vs. a glycolysis protein (but not glyceraldehyde-3-phosphate dehydrogenase as this 37kDa protein is also the nuclear human uracil-DNA glycosylase!)).
Hope this helps. Let me know if you want any more info and I'll see what I can do to help.
Good luck!
Tom
Article Determination of human DNA polymerase utilization for the re...
I'm attaching a paper that has a protocol for isolation of nuclei from human HeLa cells. If you follow this protocol, the first supernantant from the nuclear recovery step (1st low g centrifugation) would consistute the cytoplasmic subcellular fraction. Dialyze against an appropriate buffer and use this fraction for assessment of cytoplasmic proteins. Carry out the remainder of the nuclear extraction procedure to recover protein from the nuclear subcellular fraction. you can determine the efficiency of the fractionation by blotting for compartment specific proteins (i.e., a DNA polymerase of your choice vs. a glycolysis protein (but not glyceraldehyde-3-phosphate dehydrogenase as this 37kDa protein is also the nuclear human uracil-DNA glycosylase!)).
Hope this helps. Let me know if you want any more info and I'll see what I can do to help.
Good luck!
Tom
Article Determination of human DNA polymerase utilization for the re...
Ms. Mónica, thank you for your help too! Unfortunately, I don't think my teacher is quite open to buy anything right now, so I must prepare my own extraction buffers at least for now...
Mr. Winters, I read your two articles and noticed that you used dounce homogenizer to lyse the cells (to get the nuclear fractions). Well, I don't have one here at the lab and really don't know anyone around the other labs near mine who may have one. Moreover, you didn't use any detergent. I was thinking about a protocol using a detergent with a different astringency for the cell lysis as we don't have here any homogenizers and any sonicators. Besides, we don't have all the proteinases inhibitors you used. We're using here roche proteinase inhibitor tablets, do you think it can substitute that proteinases inhibitors you used? Thank you very much.