The following table describes the format of the oligonucleotide modification information listed in the "Mod" column in the Results tables on the Process and Review page.
Modification type | Description |
---|---|
FLP | Full-length product; no modification. |
Variable modification | For example, 3:A9–T15 = 2104.4033M(A9+Deamination) shows:
|
Multiple modifications | For example, 7G1–C15 = 4671.7648m[3’p](C6+C Depyrimidination) shows two modifications:
|
Unspecified modification | An unspecified modification is the addition or subtraction of a given mass of unspecified origin. For example, 6:A1–G17 = 5159.9221m(~C10+14.0137) shows:
The Enable Mass Search for Unspecified Modifications option must be selected in the processing method (Parameters > Identification > Advanced Search) for the application to perform these identifications. |
[(5')n-x] or [(3')n-x] (Nonspecific cleavage) | For example, 3:C3–T15 = 3917.6985m[(5')n-2] shows that the identified component (bases C3-T15 on oligonucleotide 3) is the result of two base losses from the 5'-terminal of the oligonucleotide full-length product (FLP). Similarly, 1:G1-A15=42595.034a[(3')n-2) shows that the identified component (bases G1-A15 on oligonucleotide 1) is the result of two base losses from the 3'-terminal of the FLP. Note: Nonspecific cleavages are reported only for oligonucleotides with no ribonuclease specified. |
3’-terminal modifications | The 3’-terminal of an oligonucleotide can be modified with the following groups:
For example, 7:G10–C21 = 3726.378m[3’p] shows that the 3’-terminal (C21 end) of the sequence G10–C21 of oligonucleotide 7 has been modified with a phosphate (p) group. |
5’-terminal modifications | The 5’-terminal of an oligonucleotide can be modified with the following groups:
For example, 1:A26-G28 = 997.15180m[5'p] shows that the 5’-terminal (A26 end) of the sequence A26–G28 of oligonucleotide 1 has been modified with a phosphate (p) group. |
Adducts | For example, 8:T1–G24 = 7342.2761m(Na+) shows that the oligonucleotide is a Na+ adduct. The application detects adducts when an identified mass is higher than the expected precursor mass by a specific amount, for example, ~22 amu higher for a Na+ adduct, based on the given charge state. The application search for many possible adducts, including Na+, 2Na+, Ca+2, and Fe+3. |
Deletion | A deletion (residual loss) is the loss of a nucleotide base within a given sequence identification. The Enable Residue Deletion option must be selected in the processing method (Parameters > Identification > Advanced Search) for the application to perform these identifications. The “Site” column in the Results table displays the deleted nucleotide base. For example, 1:U1–G6 = 1897.3107m(G4+Deletion) shows that the application detected that nucleotide base G4 was deleted from the sequence U1–G6 in oligonucleotide 1. The Site column displays “G4”. |
NOTE
A tilde (~) displayed before a base site (~G11) indicates that the position of the identified modification is approximate (less definite).