日期: | 10/18/2018 |
类别: |
Depending on what type of N-glycan moiety that is being analyzed on a TOF/TOF system, it is recommended that certain MALDI sample preparation techniques, matrices and acquisition methods be used (see table):
Note: Matrix still works the best if it is freshly recrystallized, even if this type of sample prep is a bit more time-consuming.
Carbohydrate type |
TOF/TOF system acquisition recoommendations |
Neutral glycans or reductive aminated glycans |
Positive reflector mode and positive ion MS/MS; DHB recrystallized with MeOH or EtOH as a matrix
|
Acidic glycans (e.g., phosphorylated/sulfated/sialylated to a certain extent), 2-AA-labelled glycans
|
Negative reflector mode for acidic glycan; Sialic acid containing glycans as a matrix in positive linear ion mode due to the high fragmentation in reflector mode
|
2-AB labelled glycans and permethylated glycans
|
Positive or negative reflector mode and positive ion MS/MS; DHB recrystallized with MeOH or EtOH or THAP as matrices, perhaps HCCA for large OS Positive or negative reflector or linear mode and positive ion MS/MS; DHB with ACN/water as a matrix |
O-glycans or glycosaminoglycans |
Positive reflector mode and positive ion MS/MS; DHB recrystallized with MeOH or EtOH as a matrix
|
Glycopeptides
|
Positive reflector mode and positive ion MS/MS; HCCA and CAN as matrices
|
Posted: now