Title | | » | Request for occupancy proportion report value |
Assigned To | | » | Nick Shulman |
Type | | » | Todo |
Area | | » | Skyline |
Priority | | » | 3 |
Recently got a request for a report value expressing the proportion of each peptide modified state, i.e. if the target list contains:
PESTIC[+57]EDER
PES[+80]TIC[+57]IDER
PEST[+80]IC[+57]IDER
PES[+80]T[+80]IC[+57]IDER
Then you would sum the peak areas for these 4 modified forms, and then report the peak area ratio of each to the total.
Seems like there could be all kinds of problems with this, e.g. ionization efficiency changing with modification, etc. that would likely make this not necessarily quantitatively valid, but it was suggested that a lot of people are using this metric in pharma to express purity of protein products.
Mike also seemed to feel that this would be a useful addition and that Topograph had something like this.