How to make digestion buffer? - (Feb/24/2010 )

Hi,
How do you make a 50mM Tris pH 8.0, 50mM EDTA, 0.5% SDS buffer?
Thanks,
ATH

ath on Feb 24 2010, 04:41 PM said:

Depends on the concentration of your stocks of each of those reagents.

CONC(initial) x VOL(initial) = CONC(final) x VOL(final)

If you want 50 ml of your buffer. For Tris the final conc. is 50mM and final vol is 50 ml. Plug in the intial conc. of your tris 8.0 (prob 1M), then solve for VOL(initial) and that is the volume of tris needed in 50 ml of your buffer. (careful of units, nM, M, etc)

Do this for your other two reagents, and then bring the final volume up to 50 ml with H20.

Hope thats clear enough.

Or you can work out the amount in grams of the chemicals you are using (volume=number of moles/concentration and number of moles=mass/molar mass). Dissolve the tris in 8/10s of your final volume, adjust pH using HCl, add other reagents, dissolve, and top up to final volume.

have you made any solution buffer before?

make stock solutions for all and proceed from there.
Make
1M tris pH8.0 (20x)
0.5M EDTA (10x)
20% SDS solution (40x)

Use these to make your buffer.

good luck

Thanks for all your help! I got it.