Synthesis is the first step in our production process. This is where the actual product is built as the remaining manufacturing steps refine the original product. The synthesis starts at the 3'-end of the oligonucleotide and the first nucleotide is attached to a solid phase, and then one nucleotide at a time is added to the growing chain until the oligonucleotide has reached its full length. This entire process is performed by  automated instruments. The methods used are proprietary and have been developed at SGS DNA to balance the chemical exposure of the growing oligonucleotide.

After synthesis the oligonucleotide is cleaved from the solid support. This is followed by a deprotection step where protective groups, that have prevented side reactions during synthesis, are removed. The next step is a size exclusion chromatography where material of high molecular weight is separated from material of low molecular weight (chemical residues and failures). Our careful synthesis approach gives a high yield and purity already after the first production step (approximately 60-80%) and enables us to synthesize long and complex molecules.