calculation problem in preparing the phosphate buffer - (Jul/31/2007 )

i have NaH2PO4,molecular weight is 156.01 and the NaOH with 1.0M...
if i want to prepare 25mM phosphate buffer, pH7.4
how much of the solutions i have to use to add up the total volume is 100mL?
after prepare the phosphate buffer,i need to add 1.0mM EDTA (MW = 292.25 ), 0.1mM PMSF (MW = 174.19)and 0.1mM DTT (MW = 154.25) into the phosphate buffer to add up until 50mL...
how much of EDTA, PMSF and DTT i need to add in to the phosphate buffer?

thanks a lot

see these threads

http://www.protocol-online.org/forums/inde...ic=8080&hl=
http://www.protocol-online.org/forums/inde...c=13354&hl=
http://www.protocol-online.org/forums/inde...ic=9323&hl=
http://www.protocol-online.org/forums/inde...c=13133&hl=
http://www.protocol-online.org/forums/inde...c=12737&hl=

For all your problems : prepare a cncentrated solution.
Thn pick up a volume of it, add EDTA PMSF DTT and complete with water to required volume.

For 1ml i usually add 3µl of DTT1M and 4µl of PMSF 100mM.