Editing on Michael’s Domain

Purifying Proteins with Äkta & Unicorn

Sun, 19 Apr 2026 00:00:00 +0000

Proteins (and other biomolecules) are mostly purified by chromatographic methods. There are a few vendors that have designed dedicated chromatography systems that are optimized for biomolecules such as proteins, nucleic acids, and viruses. The most well-known systems are BioRad’s NGC and Cytiva’s Äkta lines. Our faculty has recently acquired an Äkta Avant, and we are almost ready with setting it up. It’s already integrated into the reservation system. Only the automated backup system is still missing. I have been using Äkta devices since 1996, when Professor Jorma Keski-Oja bought one of the first Äkta Explorers for the Haartman Institute. The software was and still is Unicorn, but we are at version 7 now, which has a modern look when compared to the Unicorn versions from the last millennium: much less messy and cluttered. However, even after more than 10 years of development, Unicorn 7 is not yet at feature parity with the old versions. Hence, its Evaluation module offers you the option to switch back to Evaluation Classic. E.g., if you want to present personalized and stylish chromatograms in your talks, you still need Evaluation Classic! The new Evaluation module does have quick buttons to import curves into presentation software such as PowerPoint, but it is all pixel-based and therefore not easily editable after export. You want to export your curves into the industry-standard vector graphics file: SVG. You can edit it with any modern vector graphics editor, such as Canva, Adobe Illustrator, or Inkscape. When you right-click inside the chromatogram in Evaluation Classic, you have the option to save the chromatogram as a meta file. However, in the recent Unicorn version, this results in an error on Windows 11. But there is a workaround:

Exporting from Avidemux to MP4

Sat, 20 Sep 2025 00:00:00 +0000

For some reason, Helsinki University’s Unitube crashes when trying to upload an MKV file. The same used to work last year… Only proprietary formats seem to be ok (such as MP4). This creates lots of additional work for me, since I use open source tools to edit my lecture recordings (mostly to cut out unnecessary parts).However, to create an MP4 file, I need to transcode, which is a time-consuming process that requires changing many of the default settings. Below the process using the Open source software Avidemux:

Cutting mpeg movie files (mpgtx)

Wed, 04 Apr 2007 00:00:00 +0000

I recorded a documentary from TV as mpeg2. To be able to distribute it via the internet I need to shrink its size and I am using the DivX codec. But first I wanted to trim the beginning and the end. I used mpgtx , a very handy command line tool. There are Suse RPMs from Packman . The command was mpgtx -s tutkittu_juttu.mpg [00:22.50-26:55.00] -o cut.mpg