Table 2.
Molecular weight determination of oligodeoxynucleotides by MALDI-TOF mass spectrometry
| ODN | Molecular formula | Calcd MW (M-H)− | Exp. MW (M-H)− | Exp. mass errora (%) | Exp. MWb (M-H)− |
|---|---|---|---|---|---|
| D35 | C197H224N85O114P19S4 | 6320 | 6322 | +0.03 | 6319 |
| Pro-D35 | C217H278N90O119P19S4 | 6764 | 6763 | −0.01 | 6759 |
| Pro-D144 | C218H265N89O120P19S4 | 6769 | 6772 | +0.04 | ND |
| DTP9 | C197H227N76O117P19S4 | 6248 | 6244 | −0.06 | ND |
| DTP10 | C198H229N75O117P19S4 | 6248 | 6247 | −0.02 | ND |
| D35 no-pal | C199H226N83O115P19S4 | 6337 | 6342 | +0.08 | ND |
| K2007 | C216H255N66O121P21S21 | 7036 | 7037 | +0.01 | 7031 |
| K3 | C193H227N68O102P19S19 | 6329 | 6327 | −0.03 | ND |
Identity of each ODN was confirmed on the basis of the concordance between its theoretical MW and its MW determined experimentally. ND, not determined.
aExperimental mass error is determined according to the following formula: (Exp. MW − Calcd MW)100/Calcd MW.
bMW was determined after four freeze/thaw cycles.