Unprotected Universal Solid Supports
















We offer a choice of solid supports where one the hydroxy functions is protected with acetyl group, and the
other is kept unprotected. These supports do not require any initial deprotection.  However, following the
standard oligonucleotide synthesis cycle that begins with detritylation does not result in any negative effect.
Respectively, no modification to the standard synthetic cycle is required.

There are two types of universal solid supports different in the attachment of the universal linker to the solid
phase.

In the first type, the universal linker is attached via a cleavable ester bond of succinyl linker.  These
supports (products 01011-01013 and 01031-01033) are perfect for small-scale applications including the
synthesis in 96-well plates.  The
N-iPr supports p/n 01031-01033 are our latest addition to the family and
are superior t the older version with labile C3 linker (p/n 01011-01013). When labile linkers are used, the
oligonucleotides are first released from the solid phase.  With ammonia-methylamine mixture (AMA) and
concentrated aqueous ammonium hydroxide at room temperature, this step requires 15 min and 1 h,
respectively.  The dephosphorylation and the base deprotection are then carried out in solution.  The
complete dephosphorylation of P=O 2’-deoxyoligonucleotides assembled on
N-iPr supports p/n 01031-
01033  with AMA and concentrated aqueous ammonium hydroxide requires 45 min and 6 h at 65°C,
respectively.  With gaseous ammonia, following the standard protocol for the deprotection of nucleic bases
is sufficient for the completion of the 3'-dephosphorylation.  With 2'-O-substituted nucleosides, the
dephosphorylation is more rapid.  Importantly, the dephosphorylation of the 3'-terminus is more rapid than
the deprotection of nucleic bases even when the labile base-protecting groups are used.  When P=O 2'-
deoxyoligonucleotides are assembled on the supports p/n 01011-01013, dephosphorylation with AMA and
conc. aqueous ammonium hydroxide requires 1 h and 8 h at 65
°C, respectively.

In the second type of solid supports (items 01021-01023), the universal linker is attached to the solid phase
via a chemically inert amide bond.  In the final deprotection step, the solid phase should be kept in contact
with the deprotecting agent over a period of time sufficient to complete the 3'-dephosphorylation (see
above).  These supports are most suitable for large-scale applications where the time of exposure of the
solid phase to concentrated aqueous ammonium hydroxide is less critical.
For the final deprotection, the solid phase should be kept in contact with a deprotecting agent over a period
of time sufficient to complete the 3'-dephosphorylation.  The dephosphorylation of P=O 2’-
deoxyoligonucleotides is carried out using one of the following conditions:
1. Concentrated aqueous ammonium hydroxide for 2 h at 60°C;
2. Concentrated aqueous ammonium hydroxide for 12 h at 25°C;
3.  Ammonia-methylamine mixture (AMA) for 2 h at room temperature;
4. Gaseous ammonia:  for 2 h at 25°C, 10 bar.
With 2'-O-substituted nucleosides, the 3'-dephosphorylation is more rapid so that the deprotection time can
be safely reduced by 30%.

Please note that the conditions above are the minimal conditions to complete 3'-dephosphorylation. The
deprotection of nucleic bases may require a longer exposure to a deprotecting agent.

To read and download the User Guide for Universal Solid Supports, use
this link.
To download Adobe Acrobat Reader,  visit www.adobe.com.
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Unprotected universal solid supports with
labile C3 linker
Items 01011-01013
Unprotected universal solid supports with
a stable linker
Items 01021-01023
Unprotected universal solid supports with
labile
N-iPr linker
Items 01031-01033