Custom Oligo Synthesis: DNA Oligos up to 250 mer

Long Oligos up to 250 mer

Gene Link specializes in the synthesis of long oligos with complex base modifications and oligo types. This requires greater than 99.5% coupling efficiency. This can only be attained by using reagents of exacting specifications, optimized protocols and state-of-the-art instruments. Gene Link has perfected and maintains these standards.

• DNA, RNA, Chimeric, 2'0 Methyl, Phosponate, Phosphorothioate, Antisense, shRNA, Taqman available
• All modifications available. Click here for a complete list of Modifications.
• Molecular Beacons, TaqMan Probes, Fluorescent Dye labeled oligos and probes
• Antisense oligos, phosphorothioate oligos

Long Oligos Scale of Synthesis and Typical Yield of Unmodified DNA Oligos*

Gel Purified (PAGE - PolyAcrylamide Gel Electrophoresis)

51-80 mer oligo
Typical Yield

81-150 mer oligo
Typical Yield

151-180 mer oligo
Typical Yield

181-199 mer oligo
Typical Yield

200-250 mer oligo
Typical Yield

Scale

A₂₆₀ Units

nmols

A₂₆₀ Units

nmols

A₂₆₀ Units

nmols

A₂₆₀ Units

nmols

A₂₆₀ Units

nmols

200 nmol

1 umol

~0.5

~0.2

2 umol

~12

~0.5

~0.25

*NR = Not Recommended

*a. Synthesis scale and recommended oligo size is based on coupling efficiency and yield decline as the size of oligo increases. Slight deviation from the recommended scale of synthesis is accomodated. Oligos longer than 120 mer are not synthesized at below 1 micromolar scale of synthesis.

*b. Typical yield stated in the table is for unmodified random sequence oligos. Reduction in yield is observed with high GC content oligos and those forming strong secondary structures.

c. Reduced yield is expected with modified oligos. The reduction percentage varies with modification type and number of sites. Typical reduction is 10%-20% per modified site.

d. Yield of 33µg/A260 unit for DNA oligos is calculated for an ~equimolar base composition. Long stretches of a single base or homopolymers will have variable yields. Example for homopolymeric 20 mer: dA(20) = ~25ug/A260 Unit; dC(20) = ~40ug/A260 Unit; dG(20) = ~32ug/A260 Unit and dT(20) = ~37 ug/A260 Unit

The yield of modified long oligo is typically reduced by 15-20% per modified site.

Actual Trityl Coupling Efficiency of a 210 mer