Can I identify a RapiFluor-labeled released N-Glycan peak from my sample by comparing it with a chromatographic separation of part number 186007983 (Glycan RapiFluor-MS Performance Test Standard) using only UV or fluorescence detection with no mass spectrometer? - WKB53603

ENVIRONMENT

• GlycoWorks RapiFluor-MS
• Glycan analysis

ANSWER

Yes, but see the Additional Information section.

ADDITIONAL INFORMATION

Comparing a RapiFluor-MS labeled released N-glycan peak with a representative chromatogram of part number 186007983 (Glycan RapiFluor-MS Performance Test Standard) can be helpful.

However, it is not a definitive way to verify that your specific RapiFluor-MS labeled released N-glycan peak has the same structure as one of the RapiFluor-MS labeled glycan peaks as seen from part number 186007983 at the same retention time of the sample peak.

Mass spectrometry is helpful in that masses can be compared in order to better determine that an unknown RapiFluor-MS labeled released N-glycan peak is the same as a RapiFluor-MS labled N-glycan peak from part number 186007983 (Glycan RapiFluor-MS Performance Test Standard).

To better identify "unknown" RapiFluor-MS labeled released N-glycans, Waters recommends the use of part number 186007982 (Dextran RapiFluor-MS Calibration Ladder) to generate a retention time curve. This curve can be applied to all peaks from an “unknown” sample to generate a GU (glucose unit) value based on retention times. 

GU values can be calculated by using the GPC option in Empower.

Optionally, Microsoft Excel can be used to generate GU values. An add-on called SRS1 Spline is available on the internet.

Once GU values are obtained for RapiFluor-MS labeled released N-glycans, they can be compared to known GU values in a RapiFluor-MS labeled relased N-glycan database at glycostore.org.