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Trityl ON Oligos
Trityl ON Oligos
All Trityl-ON oligos are supplied on their synthesis supports without cleavage or
deprotection. Protocols
for cleavage and deprotection of normal and halogenated trityl-ON oligos are posted HERE; contact us for
procedures for other types of trityl-ON oligos. Vials, caps, and non-luer-lock syringes
will be supplied with each order.
The main reason for this is that there have been problems with poor yields on HPLC
which we believe stem either from the removal of ammonia during drying or from variations
in the composition of the buffer used for resuspending the oligos after drying. We believe
that applying the oligos to HPLC in diluted ammonia immediately after deprotection will
give better results.
We cannot supply these oligos in ammonia after cleavage and deprotection because some
trityl-ON oligos have modified residues which may be sensitive to long exposures to alkali
and also because shipping oligos in concentrated ammonia poses safety issues.
The protocols for deprotection must be followed exactly, and the OD260 from each
synthesis should be measured after deprotection to check the unpurified yield of the
oligo. The unpurified yield expected from a 1.0 micromole
synthesis is about 5 OD260 per residue; yields for the smaller scales are correspondingly
less.
We strongly recommend that, before purification, you also set aside a 1 OD260 aliquot
of each synthesis for analysis if you have problems with the oligo(s).
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