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Systematic visual inspection (clear or slightly yellowish solution with no visible precipitation).
Systematic OD measurement and concentration calculation.
Systematic PAGE or MALDI-TOF mass spec. analysis.
Systematic quality control for modified oligos. Further specific assays are performed to check the presence and functionality of the labels. These additional assays ensure a good reproducibility of the properties of the labeled oligos we offer, such as:
- fluorescent label: presence of fluorescent label on the oligo of correct length by PAGE or MALDI-TOF mass spec.
- biotin label: presence of biotin on the oligo of correct length using both a comparative migration test with a size marker and a colorimetric test
- amine label: presence of amine on the oligo of correct length using a biotin conjugation test
- phosphate label: presence of phosphate label on the oligo of correct length using an alkaline phosphatase digestion on an aliquot followed by a comparative migration test
- digoxigenin label: presence of digoxigenin label on the oligo of correct length using a comparative migration test with a size marker
- All oligos under 50 bases are QC'd by MALDI-TOF mass spectrometry
Analytical RP-HPLC or IE-HPLC profiles are provided by special request. The PAGE control is performed on 10 to 20% polyacrylamide gel to reach the best resolution for your oligos.
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