peptid conjugation to BSA ? No band in the gel? - (Nov/29/2007 )

Hi all
I conjugated my peptide with BSA by glutaraldehye method,, When I strated adding glutaraldehye the solution became turbid.. precipitated??? After that i dialysed against buffer and when loaded on to the gel to confirm ..... there was no band at all... if at all conjugation has not occured where has the BSA gone??
Can anyone please tell me

1. why precipitation has occured??
2. Why there is no band in the gel ?
3. Why even BSA is not coming in the gel ?
4. Any other reason??
5. If there is precipitation how can it be dissolved??
6.

BSA formed particles due to cross-linking by GA. A much better chemistry is to use thiol exchange method: Use SPDP to modify BSA, synthesize cys-containing peptide, conjugate the peptide to PDP-BSA through disulfide bonds.