Protein Science Facility

National facility

The Protein Science Facility provides recombinant protein production services using high throughput methods . The facility is focused on His-tagged proteins produced in E. coli and carry out sub-cloning, small-scale expression tests, litre-scale production cultures and a semi-automated two-step protein purification, but also works with tailor made protocols.

In addition PSF provides training and access to instrumentation for macromolecular crystallography and biophysical characterization. Please visit us at ki.se/psf to learn more!


  • Multi construct sub-cloning package. A set of 10 protein variants designed with seven primers, sub cloned into an expression plasmid using LIC cloning.
  • Production scale cultures. Usually 0.75 to 3 litres of TB, induction at 18C over night.
  • Protein purification. Affinity purification utilizing the His-tag followed by a size exclusion chromatography step.
  • Small scale expression and solubility screening. Per cloning package: 1 ml cultures followed by affinity purification and SDS-PAGE analysis.
  • Tailor made additions. E.g. proteolytic His tag removal, extra purification steps, additional analyses.
  • Training on biophysical characterisation instruments
  • Training on protein crystallography platform


PSF’s protein production is frequently used by scientists at both Swedish universities and companies. Proteins produced by PSF are used in biophysical characterization, antibody generation, nanoparticles, pull-downs, crystallization, structure determination, preliminary biochemical characterization, animal experiments, diagnostics, assays and technology development.

The biophysical characterisation instruments  are predominantly used for evaluating interactions; proteins with other proteins, DNA/nucleotides, peptides, or small molecule ligands. Buffer screens and ligand screens are often performed in order to find stabilizing conditions and affinity constants are often sought in combination with structure determination of complexes.

The macromolecular crystallography set-up offers use of robotics for liquid handling and crystallisation, imaging systems and microscopes for crystal visualisation, tools for crystal handling and mounting. There are also computer resources with crystallographic software, super computer access, and remote synchrotron data collection.


  • Standard protein production instrumentation.
  • Isothermal titration calorimetry. ITC
  • Thermal melt assay using differential fluorescence spectroscopy. DFS
  • Thermal melt assay using StarGazer.
  • Protein crystallography set-up.
  • Circular dichroism. CD
  • Biocore 2000


Please see our list of publications related to PSF