Glycoproteins in cerebrospinal fluid are found to be altered in Alzheimer 
patients compared to healthy control individuals. We have utilized 
micro-solution isoelectric focusing and affinity chromatography, prior to gel 
electrophoresis to enable site-specific structural determination of the N-linked 
glycans in apolipoprotein J with the use of FT-ICR MS. The albumin depletion 
method is the most suitable as prefractionation method of CSF prior to 2-DE for 
structural determination of glycoproteins in the study of neurodegenerative 
disorders.