A chemical reaction never processes completely. Impurities which occur during oligonucleotide synthesis have to be removed.

Using phosphoramidite chemistry, the main side reaction is the formation of n-x products. The longer the sequence, the more n-x products occur. After deprotection, the protecting groups will be part of the raw synthesis product.

	Yield [%] CE 99.5%	Yield [%] CE 99.0%	Yield [%] CE 98.5%
20mer	91	83	75
30mer	86	75	65
40mer	82	68	55
60mer	74	55	41
100mer	61	37	22
Theoretical percentage of full length product = coupling efficiency (CE) x (length of oligonucleotide-1)

HPSF^® Purification (High Purity Salt Free)

• Salt free
• Cleaned of any toxic synthesis and purification chemicals and n-x products
• Fast turnaround times
• Huge capacity for unmodified and Amino C6 oligonucleotides
• Various plating options (up to 384wells)
• HPSF^® purification is free of charge
• Quality control of each oligonucleotide by MALDI-TOF mass spectroscopy.

RP-HPLC Purification (High Performance Liquid Chromatography)

• Available for unmodified oligonucleotides
• Free for all modifications (except Amino C6)
• High purity due to high chromatographic separation
• Turnaround times of 3-6 working days [wd]
• Quality control of each oligonucleotide by MALDI-TOF mass spectroscopy and capillary gel electrophoresis (CGE).

HYPUR^® Purification (Purification by Gel Electrophoresis)

• Salt free
• Gel purification technology which eliminates n-x products from longmers
• Highest available quality for synthetic oligonucleotides: routinely 98% purity
• Recommended for unmodified oligonucleotides > 60mer
• Quality control of each oligonucleotide by MALDI-TOF mass spectroscopy and capillary gel electrophoresis (CGE).