I cannot find too much detail on it online. I'm lacking PEG 8000 so, i was wondering if I could use these two chemicals instead, but the amount of the chemicals is not known.
I think PEG 6000 can be used in place of PEG 8000 with the standard protocol without much difference. The higher mw gives better precipitation but 6000 should still be ok. I don't know about the use of dextran.