proteomics-HELP! - (Sep/10/2004 )

about proteomics:

the IEF dimension is performed using 7 cm or 18 cm IPG strips of selected pH range (3-10, 4-7, 3-6, 5-8, 7-10, 6-9, 3-7, 6-11, 3.5-4.5, 4-5, 4.5- 5.5, 5- 6, 5.5- 6.7).


my question is what decides the selection of a specified pH range? i have looked for answers, but can't find any.

it would help alot if anyone can tell me.

thanks!

The pH range on the IPG strips is the area in which the proteins could be resolved. If you are "fishing" for proteins which change upon a stimulation, then it is best to start with a 3-10 strip. The problem with the 3-10 is that pretty much all proteins fall in that range, so you will have alot of spots and alot of overlapping spots. Once you know the range you are interested in, you could use a higer resolution (lower range) strip, ie: the gel size will remain the same (7, 11, or 18cm) but the resolution will be much greater you will focus on just the proteins which fall in a (eg.) 4-7 range or 5-6 range.
Hope this helps.