Find solutions to product related issues. For unlisted issues please contact local Cytiva service representation.

Pressure curve issue

Poor reproducibility

Unusual column appearance

Unsatisfactory elution

General advice to achieve good performance

Before using the column make sure that:

  • Correct system has been selected in UNICORN System Control
  • Correct wavelength has been set for UV/UPC monitor
  • All tubing has been properly connected and tubing is not longer than needed
  • All connectors are free from leakage, verified by passing a leakage test
  • No tubing is folded or twisted
  • Online filter, if used, is changed on a regular basis
  • Correct buffers are used for the chosen columns and proteins
  • All inlet tubing has been immersed in correct buffer solutions
  • Enough buffer has been prepared
  • Buffers have been equilibrated to the environment temperature
  • Buffers/eluents have been degassed if necessary (e.g., in RPC runs)
  • Suitable columns have been selected for the target proteins
  • Column meets pressure requirements for selected medium
  • Columns have been cleaned and prepared according to column instructions
  • Samples have been clarified by centrifugation and/or filtration prior to sample loading
  • Samples have been adjusted to binding buffer conditions
  • Auto sampler (if used) has been prepared according to user manual
  • The fraction collector has been filled with appropriate number of microtiter plates or tubes
  • Appropriate arrangement for waste handling has been prepared



Worrying peak shape

Back pressure increases during operation

Column leakage

Poor product recovery