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qEV Columns: Shelf-Life Extended to 18 Months, and a Clear Edge Over Standard SEC Resins

Blog Post

qEV columns: 18-month shelf-life, with ~99% soluble protein and ~99% ApoB removed from plasma, and >99.99% ApoA1 removed with the 70 nm series

Thursday, October 22, 2026

Izon has two pieces of good news for qEV column users. The first is practical: columns now last longer on the shelf. The second is a new comparison showing how qEV Gen 2 columns perform against SEC columns made with standard market resins.

Shelf-life extended to 18 months

Following extensive shelf-life testing, Izon has extended the shelf-life of qEV columns to 18 months, and all qEV documentation has been updated accordingly. Labs now have more flexibility when planning orders and managing stock, with less risk of columns expiring before use. This is especially useful for groups that run EV isolations intermittently.

The extension builds on an earlier upgrade to the column storage buffer. qEV columns are stored in a buffer containing ProClin™ 200 as a preservative, a choice Izon made based on in-house studies conducted in 2023. Compared with sodium azide, ProClin™ 200 offers broader antimicrobial action and a better health and environmental hazard profile.

The data behind that choice is clear. In a microbial challenge study, four wildtype bacterial strains were incubated in PBS alone, PBS with sodium azide, and PBS with ProClin™ 200: neither PBS nor sodium azide had any antimicrobial effect, while ProClin™ 200 strongly inhibited bacterial growth at both room temperature and 30 °C. Column performance is unaffected as well. Plasma EV isolates run on columns stored in either buffer showed no difference in particle diameter or elution profiles, and no significant difference in EV concentration or protein elution.

A practical reminder: once the storage buffer has been flushed out, the column is no longer protected by ProClin™ 200. To store a used column, clean and flush it as described in the user manual, then keep it in PBS with 0.05% ProClin™ 200 or in 20% ethanol.

How qEV compares with other SEC columns

$Illustration comparing a standard SEC resin column, whose EV fraction contains more soluble protein and fewer EVs, with a qEV Gen 2 column removing ~99% of soluble protein with higher EV recovery$

Izon has published a new page comparing qEV Gen 2 columns with columns built on off-the-shelf SEC resins. The comparison is against CL-4B and CL-2B, resins widely used across the EV isolation market and once also used in Izon’s own Legacy columns, which have since been replaced by Gen 2. Gen 2 columns instead use an Izon-exclusive resin optimised specifically for extracellular vesicles. The comparison covers three key aspects.

Purity. qEV Gen 2 columns remove approximately 99% of soluble protein from human plasma, delivering significantly higher EV purity than columns using standard resins. Purity is expressed as the particle-to-protein ratio, measured using TRPS and BCA assay.

Recovery. The purity gain does not come at the expense of yield: Gen 2 columns recover significantly more EVs than comparable columns. Read More

Lipoprotein depletion. qEV Gen 2 columns remove the vast majority of lipoproteins from human plasma without a separate binding resin step. Izon tested dual-mode chromatography years ago and moved away from it, because binding resins remove lipoproteins but also lose EVs along with them. In numbers, all qEV columns remove around 99% of ApoB, and the 70 nm series achieves more than 99.99% removal of ApoA1.

The 20 nm series launched after Gen 2 and was not part of the original resin upgrade, so it is not included in these comparisons; its purity and recovery data are available on the qEV Series comparison page.

Ready for clinical translation

For groups moving towards clinical applications, qEV columns are manufactured under a quality management system certified to ISO 13485:2016, and GMP-ready columns are also available. GMP-ready columns come with Certificates of Analysis, are filled using aseptic methods with final sanitisation steps to control bioburden and endotoxin, and are made to order