Link Technologies - tools for molecular biology

Our hydrophilic Amino-Modifier 11 is particularly useful for solution-phase couplings of labels to oligos. It is often found that when using classic amino-modifiers, e.g. amino-C6, a hydrophilic spacer is required. This extends the distance of the label from the oligo. 2182 has this hydrophilicity "built-in" and can therefore be used where hydrophilic linking is needed, but the distance of the label from the oligo requires to remain short.

A MMT-protected version of this product is also available.

Where different unit prices are given for a pack size, please refer to the minimum quantity required to order at that price. These are not multi-packs, therefore enter the actual quantity of vials you wish to order.

Where different unit prices are given for a pack size, please refer to the minimum quantity required to order at that price. These are not multi-packs, therefore enter the actual quantity of vials you wish to order.

Our hydrophilic Amino-Modifier 11 is particularly useful for solution-phase couplings of labels to oligos. It is often found that when using classic amino-modifiers, e.g. amino-C6, a hydrophilic spacer is required. This extends the distance of the label from the oligo. 2193 has this hydrophilicity "built-in" and can therefore be used where hydrophilic linking is needed, but the distance of the label from the oligo requires to remain short.

This product is also available as the TFA-protected version.

Where different unit prices are given for a pack size, please refer to the minimum quantity required to order at that price. These are not multi-packs, therefore enter the actual quantity of vials you wish to order.

Recently, researchers at the University of Strathclyde have investigated the use of Thioctic Acid NHS Ester (2166) in oligonucleotide immobilisation and, in particular, demonstrate the superior conjugate stability afforded by the dithiol modification when compared to mono-thiols [1]. Furthermore, they extend the use of this modification to silver conjugation, hitherto difficult to achieve successfully.

This molecule can be attached during synthesis to the 3'-end of an oligonucleotide using a 3'-amino-modified solid support, or to the 5'-end post-synthetically to an amino-modified oligo ina similar way as, say, TAMRA NHS ester using standard coupling methods. Availability of this product therefore now allows the simple synthesis of dithiol-modified oligos for attachment to gold and silver surfaces.

Note that 20mg of product is required for a single conjugation at a 1µmol synthesis scale.

[1] Enhanced Oligonucleotide-nanoparticle conjugate stability using thioctic acid modified oligonucleotides, J.A. Dougan, C. Karlsson,W.E. Smithand D. Graham, Nucleic Acids Research,35, 3668-3675, 2007[PDF].

Where different unit prices are given for a pack size, please refer to the minimum quantity required to order at that price. These are not multi-packs, therefore enter the actual quantity of vials you wish to order.

Our hydrophilic thiol-modifier is particularly useful for solution-phase couplings of labels to oligos. It is often found that when using classic thiol-modifiers, e.g. thiol-C6 S-S, a hydrophilic spacer is required. This extends the distance of the label from the oligo. 2187 has this hydrophilicity "built-in" and can therefore be used where hydrophilic linking is needed, but the distance of the label from the oligo requires to remain short.

Do not use either ETT activator with this product as side reactions can occur.

Although thiol-modified oligonucleotides are routinely used to introduce labels such as dyes, haptens and enzymes via reaction with maleimides or acetamides, this method has been limited to the 5' or 3' end of the oligonucleotide. The use of thiol reactive labels for internal modification until now required the conversion of an amino functionality, e.g. amino-dT with thioctic acid. We have developed this thiol dT modification that can be incorporated within an oligonucleotide sequence and reacted directly with maleimides and acetamides.

Do not use ETT with this product. See the use protocol for full details.

The introduction of hydrophobic residues into oligonucleotides with a view to improving their penetration into cells is an idea that has recently met with some success. Cholesteryl-conjugated oligonucleotides have in particular been the subject of substantial interest in antisense and other studies due to the lipophilicity and ready availability of cholesterol.

Historically this has been done by post-synthetic conjugation of an amino-modified oligo to cholesterol chloroformate, however direct attachment during synthesis is much more convenient. For 3'-modification we offer 3'-Cholesterol SynBase™ CPG 1000/110. This product has a couple of notable advantages over existing products. It is not susceptible to 1,2-diol elimination as observed in some other supports. The product can also be used without IP restriction.

For 5'-modification see Cholesterol Phosphoramidite.

This product is now manufactured from an entirely plant-derived source of cholesterol (see the Blog). A BSE/TSE statement can be provided by request.

For 3'-modification see 3'-Cholesterol CPG.

This product is manufactured from an entirely plant-derived source of cholesterol. A BSE/TSE statement can be provided by request.

The introduction of hydrophobic residues into oligonucleotides with a view to improving their penetration into cells is an idea that has recently met with some success. Cholesteryl-conjugated oligonucleotides have in particular been the subject of substantial interest in antisense and other studies due to the lipophilicity and ready availability of cholesterol.

Historically this has been done by post-synthetic conjugation of an amino-modified oligo to cholesterol chloroformate, however direct attachment during synthesis is much more convenient. For this purpose, therefore, we offer 3'-Cholesterol SynBase™ CPG 1000/110(2394).

Of similar application, but comparatively less studied to date, is the incorporation of the palmitoyl moiety into oligonucletides. Recently, researchers synthesised an oligonucleotide conjugate with a 5'-terminal palmitoyl group attached through an amide bond. This has been used to modify GRN163, a thio-phosphoramidate oligonucleotide, to enhance the potency of telomerase inhibition.

Using similar synthetic methodology to that of 2394, we have prepared 3'-Palmitate SynBase™ CPG 1000/110 for direct incorporation of a palmitoyl group during oligo synthesis.

Also commonly known as spacer 18 or HEG.

Where different unit prices are given for a pack size, please refer to the minimum quantity required to order at that price. These are not multi-packs, therefore enter the actual quantity of vials you wish to order.

5-Me-dC-CE Brancher Phosphoramidite (Brancher Molecule, BM) is used to construct comb-like oligonucleotides for use in signal amplification experiments or to create nanostructures. This is achieved by synthesising secondary oligonucleotides at branching points created by incorporating one or more BMs in the target primary sequence.

The BM is designed with three masked hydroxyl groups, its structure based on 5-Me-dC. The 3'-OH of the nucleoside is provided as the reactive phosphoramidite, whilst the 5'-OH has DMTr-protection. These two groups are utilised in the normal way to synthesise the primary oligonucleotide. The third OH is levulinyl-protected and remains so during oligo synthesis. This is easily deprotected after the primary synthesis to allow subsequent secondary oligo synthesis on the free OH.