Patent ID: 6096555
Filing Date: 2000-08-01
Classification: G01N

Abstract:
A process for calculating a charge number (N) for a glycoprotein, having glycans, which comprises:(a) isolating said glycans from said glycoprotein;(b) obtaining a chromatogram, having a plot over time, by performing ion exchange chromatography on said glycans, wherein asialylated N-glycans are separated in an asialo time range, monosialylated N-glycans are separated in a monosialo time range, disialylated N-glycans are separated in a disialo time range; trisialylated N-glycans are separated in a trisialo time range; tetrasialylated N-glycans are separated in a tetrasialo time range; and pentasialylated N-glycans are separated in an pentasialo time range;(c) setting A.sub.(as) equal to the area under said plot for the asialo time range, divided by the glycan area, wherein said glycan area comprises the total area under said plot from the beginning of the asialo time range to the end of the pentasialo time range;(d) setting A.sub.(MS) equal to the area under said plot for the monosialo time range divided by the glycan area;(e) setting A.sub.(DiS) equal to the area under said plot for the disialo time range divided by the glycan area;(f) setting A.sub.(TriS) equal to the area under said plot for the trisialo time range divided by the glycan area;(g) setting A.sub.(TetraS) equal to the area under said plot for the tetrasialo time range divided by the glycan area;(h) setting A.sub.(PentaS) equal to the area under said plot for the pentasialo time range divided by the glycan area; and(i) calculating N as equal to A.sub.(as) *0+A.sub.(MS) *1+A.sub.(DiS) *2+A.sub.(TriS) *3+A.sub.(TetraS) *4+A.sub.(Pentas) *5.