creating a neg. charge on an Antibodies' Fc region - (Nov/02/2007 )

I am looking to create a negative charge on the Fc region of an Ab. The largest charge, yet maintaining stability. Any ideas? Optimal pH to create this charge? Or at what pH creates the most negative charge (Fc region or as a whole)?

Thanks in advance.

Go to pH 8.5 or 9.0.

Another possibility is to conjugate a polyanion to the sugar parts of the molecule.

hi joe,
dissolve the antibody in sodium bicarbonate buffer (pH 9.6)
all the best