I’m working with magnetic nanoparticles (10 nm) for hyperthermia approaches and I want to functionalize (coat) it with DNA (aptamer). what is the best conjugation method that could be used? – Mahmoud

Dear Mahmoud,

Thank you for your inquiry. TriLink is able to offer different attachment chemistries. Based upon your application, we would match up the functional group on the oligo based upon the reactive group of the magnetic nanoparticles. Some possible chemistries include Thiol/Maleimide or NHS-ester/primary amine of a linker.

TriLink’s DADE (decanoic acid diester) linker offers a novel way of preparing conjugates more economically and with much more flexibility. We can readily prepare 5′ carboxyl linkers. This linker can be used to conjugate to amines using conventional carbodiimide chemistry. Though less convenient than the solid phase method described in DADE: A Pre-activated Carboxyl Linker, Applications and Methods, solution phase methods may be necessary at times. The DADE linker is also useful for conjugation to amine bearing molecules.

We can also employ other attachment chemistries if you can provide the reactive group on the nanoparticles. Please contact our Product Management group to continue the discussion.

Best Regards,

I have ordered 5’end-modified RNA oligonucleotides and would now like to 3’end label them. Unfortunately, I cannot find any info on the nature of the 3’end of your RNA oligos. Is it a standard -OH group? -Eva

Dear Eva,

Thank you for your interested in our RNA oligonucleotides. You are correct, the 3′ end of an unmodified oligonucleotide would be the terminal base in your sequence with hydroxyl groups (-OH) on the 2′ and 3′ sugars.

We also offer a variety of linkers that can be used to have different chemistries on the 5′ and 3′ end of an oligonucleotide. You can use an amino linker for reactions with and activated carbonyl and a thiol linker for reactions with maleimides. The order of the chemistry performed is important as a maleimide will react with the free amine.

Please let us know if you’d like to discuss your project or quote a new oligonucleotide.

Best regards,

I would like to request quotation for a thiol-modified oligonucleotides. Is it possible to cross link the thiol-modified oligos to gold surface with succinimidyl 4-[maleimidophenyl]butyrate (SMPB)? What is the differences between 3′ C3, 3′ C6 and 3′ C6 Disulfide linker? -Lim

Dear Lim,

Thank you for your interest in TriLink’s custom oligo synthesis. Thethree thiol linkers you mention differ by the position on the oligonucleotide (5′ or 3′) and the linker length (3 or 6 carbon chain). The structure of the reduced thiol linker can be found on each product page. Thiol modified oligonucleotides are shipped as the protected thiol (for example, C6-S-S-C6, aka disulfide) to avoid dimerization. Prior to use, the disulfide can be reduced using TCEP. Thiol modified oligos can be ordered through OligoBuilder®.

Thiol modified oligos can be direclty linked to a gold surface as described by Li Z, Jin R, Mirkin CA, Letsinger RL. .

Please let us know if you have any additional questions.

Best regards,

We are interested in ordering 5′ Maleimide-modified oligonucleotides to label them with a thiol-reactive reagent for RnD assays. If we supply the thiol-reactive reagent, do you are able to deprotect the maleimide, to make the conjugation with our reagent and to purify the conjugated product? – Michael

Dear Michael,

Thank you for your interest in TriLink and the 5′ Maleimide-modifier. TriLink specializes in working closely with our customers for the individual requirements of each project including working with customer supplied material for various types of reactions.

A Product Management Specialist will be in contact via email to discuss the specifics and technical aspects of your project.

Best regards,