Sunday, September 12, 2010

Chain Terminators

Chain Terminators

The 3'-deoxy bases can be used as terminators at the 3' terminus of an oligo. They are excellent blocking groups, preventing polymerase extension from the 3' terminus. These bases can also be used internally to create a 5'-2' phosphate linkage in the oligo. All four bases are available with the deoxyribose sugar blocked at the 3' position, to give 3'-deoxy terminator G, T, C, and A. Cordecypin is an alternative name for the 3'-deoxy A terminator. These modifiers are preferred in place of dideoxy modifications. Other non-nucleoside blocker of 3'-terminus such as 3'-Spacer C3, 3'-Phosphate can also be use as 3' terminator.

Desalt or cartridge (RP1) purification is acceptable for most common phosphoramidite modifiers. However, additional purification is strongly recommended for modifiers that require NHS-ester chemistry to conjugate a dye through an amine linker such as Molecular Probes dyes.

Minimum Guarantee Purified Yield
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.

Quality Controls
Every oligo synthesized is strictly controlled for quality by using either MALDI-TOF mass spectrometry or polyacrylamide gel electrophoresis (PAGE) analysis. Final yields are determined using UV absorbance at OD260 In addition, we perform QC methods tailored to specific modifications, such as OD ratio measurement where appropriate.

For additional information, please send your request to or call us at 1-800-227-0627.

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