From Beads to Hollow Tubes: MixedLCmediA's Open-Tubular Columns Push Proteomics for the Smallest Samples

Imagine a patch of microscopic needles — each less than a millimeter long — pressed briefly against the skin. In seconds, it extracts interstitial fluid and a handful of cells, leaving no wound, no scar, and barely a sensation. This is the promise of microneedle biopsy: a minimally invasive alternative to conventional tissue sampling that could allow clinicians to detect cancer biomarkers, monitor metabolic disease, and diagnose infections using a nearly painless skin patch.

The interstitial fluid captured in these samples, among other molecules, carries proteins, metabolites, and nucleic acids that closely mirror blood plasma — but in vanishingly small quantities. When such a sample arrives at a proteomics laboratory, the analyst faces a frustrating reality: conventional liquid chromatography-mass spectrometry (LC-MS) instruments are simply not sensitive enough to extract meaningful protein data at that scale.

The sample is consumed, and the results are inconclusive.

This is exactly the kind of scenario that motivated Alexander Ivanov and Michal Gregus to advance a technology they had spent years refining in their laboratory at Northeastern University. Their goal was to use the fundamentals of chemistry and physics to make analysis systems that can better handle small samples and overall improve proteomics research. 

AnalyticalChemistryStartups recently sat down with Drs. Ivanov and Gregus, co-founders of MixedLCmediA, to learn how their porous layer open-tubular (PLOT) chromatography columns aim to close the sensitivity gap in mass spectrometry-based proteomics.

From the Lab Bench to the Marketplace

Alexander Ivanov's research career has centered on molecular characterization — starting with proteins and proteomics, then expanding into glycoproteomics, intact native complexes, glycans, and other biomolecules. As an Associate Professor in the Department of Chemistry and Chemical Biology at Northeastern University and a Faculty Fellow at the Barnett Institute of Chemical and Biological Analysis, he wears the dual hats of educator and researcher. But a persistent frustration pushed him into a third role: entrepreneur.

The core technology behind MixedLCmediA is an open tubular column format in which the stationary phase is applied as a thin porous layer on the inner wall of a narrow capillary. This technology had been the subject of research in Ivanov’s lab, as well as other research groups, for many years. Early versions showed promise but lacked robustness; they would work well for a stretch and then stop performing. 

Ivanov and his team quickly realized that even if they continued to publish papers refining the approach, the broader research community would be unlikely to adopt the novel technology. The conclusion was clear: in order for the technology to reach working scientists, it needed to become a tangible product — not just a publication in an academic journal.

That realization led Ivanov and his former postdoc, Michal Gregus, to found MixedLCmediA in 2023. The PLOT column was selected as the first technology to bring to the market.

The Sensitivity Gap

To understand why MixedLCmediA's approach matters, it helps to picture how LC columns are typically built. The standard workhorse in LC is a tube packed with tiny spherical porous beads — particles around 1.5 - 5 micrometers in diameter — that serve as the stationary phase for separating molecules. Monolithic columns offer an alternative, with a continuous porous structure instead of individual beads. 

But a third format, the open tubular column, takes a fundamentally different approach. Rather than packing material into a tube with an internal diameter of 75 micrometers or larger, the separation medium is coated as a thin layer directly onto the inner wall of a much narrower capillary with an internal diameter of around 10 micrometers.

Bead-packed column and Porous Layer Open-Tubular Column (PLOT) — Image courtesy of MixedLCMediA

This is not a new idea in chromatography — in fact, it is exactly what happened in gas chromatography (GC) decades ago. GC once relied on bead-packed columns before largely switching to open-tubular capillaries, a transition that dramatically improved performance.

The chromatographic advantage comes from the reduction in dispersive factors, such as eddy diffusion, which leads to band broadening. Improved mass transfer rates in the thin film also reduce band broadening.

Ivanov argues that liquid-phase chromatography could benefit from the same format change and that multiple technical advances have now made the timing right.

The practical advantage of this novel technique comes down to sensitivity. The open-tubular columns operate at ultra-low flow rates — around 20 nanoliters per minute, roughly ten times lower than conventional nano-LC at 200+ nanoliters per minute. As a result, they substantially increase ionization efficiency when coupled to a mass spectrometer. 

Ivanov described the cascading benefits: reduced matrix effects for each analyte band, improved ion transfer efficiency, and decreased ionization suppression. Taken together, these improvements translate to a two- to three-fold increase in the number of detected peptides and proteins compared to conventional setups, according to the team's data.

The target applications for this technology are cases where the sample material is scarce and precious. Single-cell proteomics, subcellular analysis, circulating tumor cells, and neonatal specimens all represent situations where researchers have just a tiny amount of material to analyze. 

Making It Manufacturable

Translating a laboratory curiosity into a reliable commercial product has been one of the team's central challenges. The porous layer inside the column is formed via radical-based chemistry. In earlier protocols, the process was prone to forming irregular blobs of material. These blobs could block the capillary or detach during operation, leading to clogging, short column lifetimes, and irreproducible results. 

Many inventions by the team, including those implemented by Gregus, have focused on designing a uniformly thin stationary phase layer firmly attached to the tube wall. The team has also explored different chemical compositions to support various separation modalities.

The company has a patent application on its technology and has built a working prototype. The prototype consists of an optional trap column, a PLOT analytical column, and an electrospray ionization (ESI) emitter connected via zero-dead-volume fittings. All of these components are to be enclosed in a cell phone-sized case designed to be compact, durable, and easy to handle.

Challenges on the Road Ahead

What is next for MixedLCmediA? The near-term goal is to make the system truly plug-and-play, so that any lab associate can connect the product to a standard LC platform and run without specialized expertise or hands-on optimization. The product also needs to be robust enough that it can be shipped across the country or around the world and work immediately.

The longer-term challenges are less technical and more organizational. Like most startups, MixedLCmediA is looking for collaborators and partners to help the team continue to grow a successful business. They are actively seeking support in market analysis, business development, and the many adjacent activities that bridge the gap between a working prototype and a sustainable company.

Early collaborations with leading institutions as beta-testers are underway, and the next milestone is a pilot product stage: a thoroughly evaluated, reliable platform ready for broader dissemination.

Seeing What Was Previously Invisible

When ACStartups asked Ivanov about his vision for impact, he described a desire that goes beyond any single application. He hopes to enable researchers to pursue entirely new lines of inquiry by conducting experiments on very small samples that were simply impossible to analyze before. Rather than positioning the PLOT column system as a tool for one killer application, Ivanov envisions it as an open platform with the opportunity to catalyze various scientific discoveries.

"I hope to be surprised by things coming out using our columns and enabling the analysis," Ivanov told ACStartups.

Gregus echoed the sentiment from a more practical angle, noting that open-tubular column technology for liquid chromatography has been explored in the literature for a while but has never been commercially available. Making it accessible and putting it into the hands of working scientists is, for him, the point. And someday, this technology might be the very thing that saves the life of a baby in a neonatal intensive care unit. 

To learn more about MixedLCmediA and their PLOT chromatography column technology, visit mixedlcmedia.com.