All our oligonucleotide undergo vigorous process monitoring and strict quality control. Length and labeling are systematically controlled by PAGE and characterized by MALDI-TOP mass spectrometry analysis. Quantity is determined and validated by UV Absorbance at 260 nm.
You will receive a Quality Assurance Certificate that includes quantitated yield, melting temperature, MW and µg/OD with every oligo. You will also receive an additional label for use in your records or on an additional vial.
A wide variety of modifications can be incorporated into an oligonucleotide at the time of synthesis, using aspecialized phosphoramidite chemistries for labeling. However, certain modifications require the use of post-synthetic conjugation strategies in which a primary amine modified oligonucleotide is covalently attached to a dye via NHS ester chemistry. Other cross-linking chemistries are also available depending on particular project specifications. Single HPLC purification is recommended when using phosphoramidite oligo chemistry, otherwise dual HPLC is required for post-synthetic labeling.
Due to the chemistry of many modifications, yield will be approximately 40 - 60 % less than a standard oligo. Please see our yield chart for details.
Expected shipment time for common dye modifiers is 3 - 5 working days. More exotic modifications are usually completed within 5 - 7 working days.
Light sensitive material. Fluorescent dye-labeled oligos are more fragile than unmodified oligos. Their ability to fluoresce will decrease over time. To ensure high quality, store the oligo dry at -20°C in small aliquots. Note also that fluorescent dye-labeled oligos should be stored in the dark as light can slowly degrade the fluorescent moieties.
For optimal long-term storage of fluorescent dye-labeled oligos except Cy5 and Cy3, it is recommended that the oligos be resuspended in a slightly basic solution (i.e., TE at pH 8). If brought to a pH below 7, it has been shown that the oligo can begin to degrade and may be unusable within a few weeks. Cy5 and Cy3 begin to degrade at a pH above 7. For best results, resuspend Cy5 and Cy3 labeled oligos at pH 7, aliquot, lyophilize, and store at -20ºC. Fluorescent dye-labeled oligos can be used up to 6 months from purchase when stored at -20°C in the dark.