FAQs
How can I release the N-linked glycans from my glycoprotein?
There are two main techniques commonly used to liberate glycoprotein N-linked glycans for glycosylation analysis - hydrazinolysis and endoglycosidase treatment. Our Guide to Glycosylation Analysis covers some of the considerations for choosing between these release methods.
How can I stop the sialic acids falling off my glycans?
Sialic acids are tricky things. In our experience, the purer the glycan sample the more likely the sialic acid residues are to fall off. There are some sensible precautions though:
- Avoid the combination of acidic pH and elevated temperature. Wherever possible, keep the pH in the range 6-9 and the temperature below 30 C.
- Be careful when drying glycan samples by centrifugal evaporation or rotary evaporation. When you use these procedures try to keep the temperature below 25 C. Lyophilization (freeze-drying) can be safer with respect to sialic acid degradation but with this technique there is a greater danger of losing the entire sample when the vacuum is released.
Which are the best fluorescent tags for glycan analysis?
The following table shows the most widely used fluorescent glycan tags for glycoprofiling by HPLC, CE and MS:
| Fluorescent Glycan Label | Main Applications | Fluorescence Wavelengths and Common Analysis Methods |
|---|---|---|
|
2-AB (2-aminobenzamide) |
Oligosaccharide Profiling by HPLC and MS |
Λex = 320 - 360 nm, Λem = 420 nm HPLC (amide, C18, AEX, HPAE-FD, PGC), ES-MS, MALDI-MS |
|
2-AA (2-aminobenzoic acid) |
Oligosaccharide Profiling by HPLC and MS Monosaccharide Profiling by HPLC |
Λex = 320 - 360 nm, Λem = 420 nm Oligosaccharides: HPLC (amide, C18, AEX, PGC), ES-MS, MALDI-MS Monosaccharides: HPLC (C18) |
|
APTS (8-aminopyrene-1,3,6-trisulfonate) |
Oligosaccharide Profiling by CE |
Λex = 455 - 488 nm, Λem = 510 - 520 nm CE |
|
AA-Ac (3-(acetylamino)-6-aminoacridine) |
Oligosaccharide Profiling by HPLC |
Λex = 382, 445 nm, Λem = 525 nm HPLC (amide, C18, AEX), ES-MS, MALDI-MS |
|
DMB (1,2-diamino-4,5-methylenedioxybenzene) |
Profiling of Human vs Non- Human Sialylation by HPLC |
Λex = 373 nm, Λem = 448 nm HPLC (C18) |
Key: AEX = anion exchange, HPAE-FD = high pH anion exchange with fluorescence detection, PGC = porous graphitic carbon
Featured products
-
Glycan HPLC Columns
For analysis and purification of labeled glycans
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N-Glycans
For use as biological reagents and standards during analysis
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Glycan Purification Kits
For purification of glycans after procedures such as labeling and enzyme treatments
How to Order
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