I would like to collect PBMCs from patients to later extract protein and do western blotting eventually. I wonder if there is a way to preserve the protein or the cells (in the field), so my samples won't ruin with time as I'm supposed to do a flow cytometry protocol on other samples in the same day.
I tried to use RNAlater from Life Technologies, as they said I can preserve RNA or protein in it. I put the cells there with 5x the volume of RNAlater, left them in at 4C for 3 days to test. Then I extract the protein and there was no much protein which was confirmed with the western blotting. I got no GAPDH bands.