40kDa protein for ladder - (Jun/25/2007 )

hi all! i'm looking to make my own ladder as i am having troubles with bought in models (and cannot afford to keep buying and trying new ones!) im looking for protein standards at ~3kDa,20kDA, 40kDa and a higher MW protein about 80kDa.
so far i have found Insulin a 2,530Da, trpsin inhibitor from soybean 20kDA im stuck as what to use for my 40kDA and 80kDA marker. has anyone any ideas?
i will be running simple 1D SDS Page gels with these standards.
thanks!

---

recently we bought a ladder that starts from 10 kda,
10, 20, 25, 37, 50, 75, 100, 150, 200 and 250 Kda ladder
its very good and ladder can be seen through the gel at the time of electrophoresis

---

very good. who make it? is it expensive though?

---

take a look at sigma-aldrich.com. they offer various purified proteins for SDS or native PAGE; ovalbumin is ~45 Kda; beta-actin ~42;

soybean trypsin inhibitor (for inhibitor studies) is relatively impure and makes some extra bands

---

The biorad's precision protein standards are good. They have 10, 15, 20, 25, 37, 50, 75, 100, 150 and 250kD band (most likely what T. reesei mentioned). I would recommend either the Dual color or the kaleidoscope one (both are Precision Protein Standards, since they also have kaleidoscope standards, which are different). Not too expensive. But this type don't have the 3kD that you want. They do have a low range marker (which have from 4kD to 36kD), and broad range (7.6kD to 216kD). If you don't want either of these, you can check for the proteins that they use in their marker. In BioRad catalogue, they tell you what protein was used for each band.

---