IEF problems/ MAbs

[Ctro Inmunologia Molecular]

   Does anybody know how can detect by IEF problems with monoclonal 
 
   antibody like deamidation,loses of carbohydrates,glycosilation and 
 
   others.If my protein's isoelectric point (pI)  changes, how can I 
 
   say which one of these mecanism are responsible for pI change?
 
   
 
   Advices,references and practical sugestions will be welcome.
 
   
 
   Thanks in advance
 
   
 
   LOBVI
 
   monoclon at infomed.sld.cu