IgG's "epsilon" - (Apr/20/2005 )

Hi there!

does anybody know the epsilon value of IgG?

I'm purifying Ig from rabbit serum on protein A beads, and I'd like to quantify my purified mixture.
The idea would be to check the OD at 280 nm (right?...). Still, I don't known the molar extinction factor (what is the english translation??), value I need to determinate my IgG concentration.


thanks all for replies!!

manu

hi
i'm not very good at physical properties of proteins, but i do remember that at 280nm, only tryptophane has a good cofficient of molar extinction. hence i suppose a standard bradford assay would do the job... it's just an idea.

fred

For most whole IgGs, epsilon = 203,000 cm-1M-1.
Replace this in your formula by 1.43 for the concentration in mg/ml rather than in M.