The pI-Trap åcelus is the second generation of a sample prefractionation device jointly developed by Biomotif AB and the Karolinska Institute. It provides separation of complex mixtures based on capillary isoelectric focussing (cIEF). This separation process is completely orthogonal to the commonly used hydrophobicity based HPLC separation. The system allows unattended separation overnight and collection of typically 20-25 fractions per sample.

The separation takes place in a unique multi-junction pI cell, which allows the separation even extremely complex mixtures such as serum or plasma. The open tube setup avoids clogging of the system as it can be easily flushed. Samples are separated in an ampholyte free solution, are automatically collected in well plates in a refrigerated environment and can be used for further sample processing such as digestion or direct analysis. The ampholyte free samples are particularly well suited for direct mass spectrometric analysis.

The typical separation time scale is about 1h per sample, shorter turnaround times are possible depending on the actual separation problems. For further subsequent sample processing, the system can handle in excess of 100µg protein in a single separation, which even allows for rapid microLC separations in a clinical proteomics setup for hundreds of samples.

Application examples:

  •  Sample clean-up and simplification for proteomics
  • Clinical biomarker research
  • QC of biologics (e.g. screening for Lys presence at mAb heavy chains or pyroglutamate formation)
  • Analysis of glycosylation heterogeneities, analysis of sialic acid content and distribution
  • Analysis of deamidation processes (converting Asn to Asp or Gln to Glu)


  • Significantly higher ID numbers in proteomics experiments, >40% more ID’s from human cell digest in TMT based quantitation experiments on QExactive plus, 70% more protein ID’s on human cell digest in LF quantitation experiment on Orbitrap XL
  • Sample in ampholyte free buffer, ready for direct mass spectrometric analysis
  • Robust open tube system with minimal losses (>90% recovery rate)
  • Much higher sample load than capillary LC allowing for prefractionation with subsequent analysis of the individual fractions with the need for repetitive fraction collection
PI Trap

Thank you for delivering such a nice instrument!

I would like to thank you again for your efforts in setting up our High Mass Q-Tof-MS and in introducing my students to the basic operating principles of the instrument. We performed the first measurements this week, which went really well. You did a great job and we are very happy with our new toy.

Prof. Dr. Andrea Sinz
Martin-Luther University Halle-Wittenberg

Thank you for the repair and training.

I would like to take the opportunity to thank you for the repair of our Quattro Micro and subsequent ‘hands on’ training course. The training course was very useful, generating positive feedbacks from the attendees. We look forward to receiving the training course certificates.

Dr. Nancy Weisbach
Across Barriers GmbH

MS Vision is our long lasting services partner

MS Vision is our long lasting services partner for the maintenance and troubleshooting of our entire fleet of LC-MS/MS instruments. For us, their eagerness to extend their portfolio with new services and collaboratively identify ways of improvements is very much appreciated and fundamental in the reduction of instrument downtime that has been achieved.

Niels Martha
TLR International Laboratories

Installation of five Thermo mass spectrometers at Biomedicum, Karolinska Institutet, Stockholm

The team of MS Vision has recently helped us to relocate our entire mass spectrometry lab, including five Orbitrap instruments (three Q Exactive series, one Elite and one Fusion) within the campus of Karolinska Institutet. Both the preparation and execution of this delicate operation was performed with absolute profession and accuracy. After the careful move, it took only two days to get all systems up and running like they would have never been down for a second. Needless to say how grateful we are for MS Vision for this excellent job!

Akos Vegvari, PhD
Proteomics Biomedicum, Karolinska Institutet

“I love how MS Vision makes us better!“

Boris Krichel

Thank you for your cleaning effort on our Sciex 5500

Since last Wednesday we ran around 100 samples, everything is perfect (better sensitivity and linear dynamic range).  I have checked some data back to the last October, since I know what I am looking for, it seems that the charging problems started around December/January. Next time I will realize it much earlier.  Thank you both for your cleaning effort 😉


Manuel Mazenauer