Statements for the 100th PurePrep Chorus

Chemitope_Glycopeptide Chorus2

At the end of last year, we sold the 100th PurePep®Chorus unit to the talented team of scientists at Chemitope Glycopeptide. It was delivered, installed, evaluated, and now Baptiste Aussedat, William Walkowicz, and their team are sharing their experience with the instrument.

The decision for choosing PurePep Chorus

Having successfully prepared a complex glycopeptide for phase I clinical trial at gram scale with our PTI Tribute peptide synthesizer, we logically looked at what upgrade PTI was offering in order to sustain Chemitope Glycopeptide’s growth. We needed to speed up our process and increase our output, and as we had already experienced the reliability of PTI automated peptide synthesizers, the PurePrep Chorus was a straightforward decision.

How the system is going to impact your work

One characteristic of Chemitope Glycopeptide’s technology is that it requires off-resin protected peptides of the highest purity. With up to 6 reactor positions each suited with individual induction heating and individual protocols, the PurePrep Chorus will allow us to screen multiple conditions and accelerate our R&D process, and with optimal conditions in hand, we will be able to increase our output by producing up to 6 sequences at the time.

Performance so far

Our PurePrep Chorus has been installed for two months and while we are still discovering all its full synthetic capabilities, we can already clearly see the added value. We can produce more, get results quicker, while maintaining our high-quality standard. For example, we can easily scout effective conditions for a 40mer sequence overnight using the intuitive software that pilots the instrument. As a bonus, consumption of solvents has decreased compared to other automated systems we have used.

Key features that are of benefit

Our glycopeptide synthesis technology requires the use of precious amino acids synthesized in-house. In addition of the 27 amino acid positions available on the instrument, 6 “single-shot” positions could be used to deliver the exact amount of building block needed, therefore saving expensive resources. To further tailor the coupling conditions, these precious building blocks could be installed in the sequence using a dedicated activating agent. Another key to our process is the use of exotic protecting groups which are removed on solid-support post synthesis. The PurePrep Chorus allow us to load and use the corresponding reagents for these selective deprotections furthering automating our process with precise control.


Only 20 minutes are needed to prepare reagents fresh and program the instrument for synthesis. Working with amino acid stock solution, a week’s worth of reagents can be prepared in one sitting, simplifying the setup. The PurePrep Chorus is piloted from a mobile tablet which lets us program new syntheses in the lab or at our desk. It is equipped with an intuitive and convenient software which gives an overview of the resources needed for each synthesis, but also allow us to use preestablished methods to investigate the impact of the modification of one factor in the method or to simply repeat a synthesis.

Chemitope Glycopeptide