Why have the default buffer volumes changed for the qEV columns?

We have replaced the term 'Void Volume' with the term 'Buffer Volume' - see here.

Following an in-house study by the Izon R&D team in May 2021, we have updated the buffer volumes for all our columns to improve the yield and purity of the target particles in the purified collection volumes.

Experiments for the qEVoriginal column found that particles were eluting after 2.7 mL in both the 35nm and 70nm columns, so the default buffer volume has been lowered to 2.7 mL in order to collect these.

The buffer volumes for the qEV2 and qEV10 have been increased to  14.1 mL and 21.4 mL respectively as the original settings were found to contain almost no particles before these values and were diluting the samples unnecessarily.

The default buffer volumes for columns are now:

These will be the new defaults in AFC V2.3.2.

If you need to use the old buffer volumes for your experiments to be consistent, do not update your AFC to version 2.3.2 or later, this will keep the default buffer volumes of 1.0 mL (qEVsingle), 2.85 mL (qEVoriginal), 14.0 mL (qEV2) or 20.0 mL (qEV10).

Contact support@izon.com if you require old firmware versions or have any questions.

The qEVsingle columns were found to have different buffer volumes depending on the resin type. Therefore, the default buffer volume for the qEVsingle/35nm has been decreased to 0.8 mL, as it was found that on average 2.4e10 particles per mL were present in this fraction.


The default buffer volume for the qEVsingle/70nm remains at 1.0 mL, as the 0.8-1.0 mL fraction contains on average 1.0e8 particles per mL. This was excluded as it causes significant dilution of the total collection volume if included. However if sample dilution is not critical to your application, then the buffer volume can be set to 0.8 mL to collect this small amount of particles.