Regarding the glycoprotein standards to be used, a positive control would be
the popular bovine fetuin or transferrin.
A negative control is a tough one as seen in the discussions.
After considering recombinant proteins, I found Affinity purified BSA (Pierce,
cat no. 30444=6x10mg or 30443=1g). I used this as a carrier during
deglycosylation reactions and this has given me virtually no background when
analyses were done by HPAE-PAD.
Please let me know how it works for you.