This page summarizes all the peak assignments accepted by the user thus far.
The user still has the option to reject the assignments in this page.
An example screenshot of a completed N-glycan assignment to a monoclonal antibody is shown in the screenshot below.
The bar chart shows each peaks relative abundance where a
tick
indicates user acceptance of the peak.
Each bar can be clicked to reveal the
peak shifting output.
The pie charts give the distribution of sialic acids, GlcNAc antennae, galactose and
other monosaccharides among others.
The tables present the N-glycans already assigned in
the user accepted peaks. GlycanAnalyzer does not use threshold values to assign confidence levels to its annotations. Instead, three confidence levels for each glycan
annotation is defined as follows:
- Weak: There are no mass or peak shifts detected. Glycans are assigned using similarity to database GU values only.
- Medium: There is a mass detected and a similar GU in the database for the glycan annotation. However, no peak shifts could be
detected - this often happens for smaller peaks.
- High: There was a mass detected, a similar GU found in the database and the peaks movements could be traced from the
Undigested to profile to the final exoglycosidase applied.
An example summary page is shown below.
Part (a) shows that peak 3 has two pieces of evidence an observed mass and similar
GU to average evidence in public databases.
Part (b) shows that peak 4 has three pieces of evidence:
mass, shifting peaks and similar GU to database GU values.
Peak 4's N-glycan assignment can be considered to have high confidence
while peak 3's has medium confidence.
The weakest level of supporting evidence is GU similarity alone.
Clicking on the button 'Mass' returns the mass spectrum for this peak and possible annotated m/z peaks for the current glycan.
Clicking on the
'Shifts' radio button returns the score calculation and all possible UPLC and MS peak shifts.
The 'Glucose unit' radio button can be clicked to visualize the GU evidence in glycostore.