Prepared by Biosynthesis, Inc., all right reserved.

Solid supports and biomolecules include:

• Small molecules (drugs, fluorescent dyes ……),
• Peptides, proteins (carrier proteins, antibodies, enzymes ……)
• Oligonucleotides (DNA, RNA, BNA ……)
• Lipids, carbohydrates
• Drug delivery reagents (PEGs, PGAs, dextrans, dendrimers ……)
• Nanoparticles (gold nanoparticles, Q-dots……)
• Solid support (magnetic beads, agarose, silica gel, glass, polystrene ……), and more

Per request, and depending on the nature of the biomolecules, a large variety of chemistries are practiced in Biosynthesis:

• Carboxylic acid activation and amine/NHS ester reaction
• Thiol/maleimide reaction
• Thiol exchange
• Diol oxidation and reductive amination
• Hydrazone and oxime formation
• Click chemistry, including copper-free click chemistry

And more when necessary. Normally one or two chemistries are needed to prepare a conjugate.

Advantages:

• Surface amine and/or carboxyl group used for conjugation
• Zero spacer conjugate possible. Spacer may be incorporated upon request
• Reaction in slightly acidic or neutral solution
• Very stable conjugate

Disadvantages:

• Surface modification may affect its solubility and Defunctionalize the molecules
• Efficiency may be low when using carboxyl group for conjugation
• If molecule contains both carboxylic and amino (or thiol) groups, dimerization may occur

Advantages:

• Surface thiol group used for conjugation
• Normally a spacer is needed when introducing the maleimide group
• Reactions in slightly acidic solution and conjugations are selective
• Stable conjugate

Disadvantages:

• Surface modification may affect its solubility and Defunctionalize the molecules
• Maleimide may be hydrolyzed, and the conjugate may be dissociated if left in basic solution for a long time.

Advantages:

• Surface thiol group may be used for conjugation
• Normally a spacer is needed when introducing the pyrimidium disulfide unit
• Reaction in neutral or in slightly basic solution
• Conjugate is cleavable chemically (by DTT or DCEP), in cell, and in vivo

Disadvantages:

• Surface modification may affect its solubility and Defunctionalize the molecule
• Disulfide bond of the conjugate may slowly exchange with other thiol-containing compound

Advantages:

• Surface hydroxyl groups used for conjugation, especially useful when using sugar unit for conjugation
• Zero spacer conjugate is possible, spacers may be introduced
• Reaction in neutral or slightly basic solution
• Extremely stable conjugate

Disadvantages:

• Surface modification may affect its solubility and Defunctionalize the molecule
• Conjugation efficiency may be low
• Trace amount of NaIO4₄ and NaBH₃CN may exist in the sample, and may cause problem in some essays

Advantages:

• Normally a spacer is needed when introducing aldehyde, hydrazide or oxyamine group by using surface amine groups
• Surface hydroxyl groups may be used in combination with NaIO₄ oxidation
• Reaction in near neutral solutions or slightly basic conditions
• pH sensitive conjugate, the conjugate can be reduced to be extremely stable

Disadvantages:

• Surface modification may affect its solubility and Defunctionalize the molecule
• Conjugate may not be very stable, especially for hydrazones
• Some cross-linkers are patented and may have legal implications for commercial usage

Advantages:

• Normally surface amine or thiol group is used for conjugation
• Normally a spacer is needed when introducing azide and alkyne groups
• Reaction can be performed in any type of solution, reactions are highly selective
• Very stable conjugate

Disadvantages:

• Surface modifications may affect solubility and Defunctionalize the molecule
• Trace amounts of remaining Cu(I) may be harmful to some essays, this is overcome by Cu-free click chemistry but reagents are more expensive

We Specialize in:

• Peptide synthesis and conjugation
• Oligonucleotide synthesis and conjugation
• Antibody conjugation
• DNA/RNA transcription
• Protein expression
• Customized bioconjugation services

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