Hello, chromatographers!

My lab is interested in working with bacterial
cultures using HPLC. Has anyone
out there had success working with bacteria
without using sample filtration? We'd prefer
to use a benchtop centrifuge. A centrifuge
can take out the vast majority of bacteria
from a sample, but bacteria are really small
(smaller than a precolumn filter pore),
so it seems risky. Does anyone have any
information about this?

thanks!

The column will clog after some time, depending how good the centrifugation is. The column costs $400. Without filtering, you may get 200 injections out of it. That's $2.- per sample. Do you care?

Why not use a guard column, and discard that when pressure rises?

I agree with the previous posting as work with microorganisms will lead to clogged columns soon but a 15 min full-speed centrifugation should remove most of intact bacteria. Another problem might remain with proteins from lysed bacteria that are normally present in culture supernatants. So a precipitation step using Sulfosalicylic acid or Acetonitrile can improve the situation. Most favorable would be a solid phase extraction step that removes whole organisms by size exclusion and macromolecular contaminations by adsorption/ exclusion mechanisms.

Centrifugation + microfiltration could do the trick. If there is a protein problem you can get rid of most of them with an ultrafiltration (there are systems with which that can be done in one step with the microfiltration).

Thanks, all!