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[jiro_killua]

I'm following the acid extraction of histone from Nature Protocol vol2(6) p1445 (Shechter et al) before doing western of H3K4me3

There's one step that's not very clear and I'm trying to ask for opinion here

After nuclei isolation, I resuspended the nuclei pellet in 400ul of 0.4M H2SO4
Incubate overnight with a rotator

But the protocol didn't say whether it's at room temperature or at 4C

Because all the other steps in the protocol are at 4C (like centrifugation steps right after this step is also in a pre-cooled centrifuge), I assume this step is also at 4C

Or is it?

After this step, I'm supposed to centrifuge at max speed to pellet all the cell debris and precipitated proteins and collect the supernatant, which contain the histones

But I'm worried if the incubation with H2SO4 is at 4C, the histones will precipitate
I'm equally worried if the incubation is at r.t., degradations will occur....

Any suggestions or past experience are welcomed.