Editing Glycomics (section)

===Multiple Reaction Monitoring (MRM)===
Although MRM has been used extensively in metabolomics and proteomics, its high sensitivity and linear response over a wide dynamic range make it especially suited for glycan biomarker research and discovery. MRM is performed on a triple quadrupole (QqQ) instrument, which is set to detect a predetermined precursor ion in the first quadrupole, a fragmented in the collision quadrupole, and a predetermined fragment ion in the third quadrupole. It is a non-scanning technique, wherein each transition is detected individually and the detection of multiple transitions occurs concurrently in duty cycles. This technique is being used to characterize the immune glycome.<ref>{{cite journal |last1=Flowers |first1=SA |last2=Lane |first2=CS |last3=Karlsson |first3=NG |title=Deciphering Isomers with a Multiple Reaction Monitoring Method for the Complete Detectable ''O''-Glycan Repertoire of the Candidate Therapeutic, Lubricin. |journal=Analytical Chemistry |volume=91 |issue=15 |pages=9819–9827 |date=11 July 2019 |doi=10.1021/acs.analchem.9b01485 |pmid=31246420|s2cid=195759019 }}</ref><ref name="immune_glycan">{{cite journal |vauthors=Maverakis E, Kim K, Shimoda M, Gershwin M, Patel F, Wilken R, Raychaudhuri S, Ruhaak LR, Lebrilla CB | title = Glycans in the immune system and The Altered Glycan Theory of Autoimmunity | journal = J Autoimmun | volume = 57 | issue = 6 | pages = 1–13 | year = 2015 | pmid = 25578468 | doi = 10.1016/j.jaut.2014.12.002 | pmc=4340844}}</ref><ref>{{Cite journal|last1=Flowers|first1=Sarah A.|last2=Ali|first2=Liaqat|last3=Lane|first3=Catherine S.|last4=Olin|first4=Magnus|last5=Karlsson|first5=Niclas G.|date=2013-04-01|title=Selected reaction monitoring to differentiate and relatively quantitate isomers of sulfated and unsulfated core 1 O-glycans from salivary MUC7 protein in rheumatoid arthritis|journal=Molecular & Cellular Proteomics|volume=12|issue=4|pages=921–931|doi=10.1074/mcp.M113.028878|doi-access=free |issn=1535-9484|pmc=3617339|pmid=23457413}}</ref>

'''Table 1''': Advantages and disadvantages of mass spectrometry in glycan analysis

{| class="wikitable" border="1"
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! '''Advantages'''
! '''Disadvantages'''
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*Applicable for small sample amounts (lower fmol range)
*Useful for complex glycan mixtures (generation of a further analysis dimension).
*Attachment sides can be analysed by tandem MS experiments (side specific glycan analysis).
*Glycan sequencing by tandem MS experiments.
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*Destructive method.
*Need of a proper experimental design.
|}