July 11, 2016

Jumpstart your chromatography runs

By Tuomo Frigård, Scientist at GE Healthcare

Would you like to get guidance on your ÄKTA chromatography system? Here, I share tips from discussions with my R&D colleagues that can help you get a quick-start on your protein purification run. I will also share a few maintenance tips to help keep your system in a good shape.

Tips for ÄKTA system users

Here, I have collected some useful tips when running ÄKTA pure and ÄKTA avant protein purification systems:

  • Annoying signal disturbances during a run can be reduced by purging the pumps and flow path from air. Also, use the flow restrictor to prevent air bubbles from forming in the flow path.
  • To save time and buffers, remember to prime buffers into the system in reverse order of usage (last primed–first in).
  • If the purification results do not turn out as expected, some troubleshooting might be required. There is a lot of useful information stored in the result file that can be used for troubleshooting. If you wish to evaluate data from an ongoing run, use the vertical marker (found by right-clicking the chromatogram) and set a reference point.
  • The BufferPro functionality can be used to avoid spending time on buffer preparations. If needed, there is also a support tool in the UNICORN software for manual buffer preparations.
  • To extend durability of systems and columns, too high backpressure during a chromatography run should be avoided. Using refrigerated buffer solutions or running the system in a cold room will create higher system backpressure and might require lowering the flow rate.
  • The conductivity signal is used to monitor gradients during elution. However, keep in mind that the signal is not linear to the salt concentration. So, using the signal for specific calculations (e.g., determination of ion concentration) requires special caution.

Remember to keep your system in good shape. Here are some maintenance tips:

  • For accurate detector readings, remember to frequently zero/calibrate the pressure sensors and UV detector.
  • Clean the system between runs and fill the system with storage solution (e.g., 20% ethanol) when leaving it unused for longer periods.
  • To maintain efficiency of the piston pump, change the solution in the pump rinse system every week.
  • Change the in-line filter every month, or even more frequently if you are running sticky samples.

I hope you found these tips useful. Would you like to get more useful tips? The Good ÄKTA system practice cue cards include practical tips, run essentials, recommendation on wash and cleaning procedures, as well as a troubleshooting guide. Download the cue cards and keep them next to your system to avoid spending time on how to use your system, and instead, get on with your chromatography run.

In my upcoming blog post, I will share tips on how to simplify and gain efficiency in method creation.