Setting up a new lab with FIDA: a conversation with Dr. Nikolaos Louros

Dr. Nikolaos Louros is a professor of biophysics at UT Southwestern Medical Center in Dallas, where he recently set up a new laboratory and chose Flow Induced Dispersion Analysis (FIDA) as one of its foundational instruments. In a conversation with Fidabio, Dr. Louros explained why it was, in his words, an obvious choice, and how his group puts it to work. This is a summary of what he said.

Why Dr. Louros chose FIDA for a new lab

For a newly established lab, the hardest constraint is having the practical capacity to do the science you plan while resources are still tight. That put a premium on versatility, and it is what made FIDA, for Dr. Louros, the easiest of the instrument choices in front of him.

"It would be very frustrating if you have all of these interesting things you're planning to do, and you simply don't have the practical capacity to do them. So FIDA was exactly the reason why I wanted to include it in the lab. I think it's an excellent resource for newly established labs because it's a very versatile instrument," Dr. Louros said.

That versatility is concrete: a single platform that measures binding interactions, affinities, kinetics and stability and runs quality control, across proteins, nucleic acids and even small molecules, all in near-native conditions. Add low operational costs, ease of use and a fit with medium- to high-throughput workflows, and for a new lab the case was, he said, obvious.

"It was the easiest choice. You can work with different types of molecules, proteins, nucleic acids, even small molecules, which are challenging for other instruments," Dr. Louros said.

What FIDA makes possible: amyloid polymorphism and AI-designed proteins

A central focus of the Louros lab is amyloid polymorphism, the way a single aggregation-prone protein can adopt different structures that are linked to different forms of disease. Understanding that shape-shifting, and designing molecules to steer or stop it, is the goal, and the group pursues it with a hybrid approach that pairs AI-based computational protein design with wet-lab validation. Two FIDA capabilities recur here. The first is its direct, absolute hydrodynamic-radius readout, which matters when the data feeding the next design cycle has to be real and measurable rather than an indirect signal: a quick FIDA measurement checks whether a computationally designed construct actually folds as predicted.

"Having the ability to measure hydrodynamic radius, for instance, is a very quick first step to measure and see if what we designed computationally actually folds the way that we expect it to in our experiments," Dr. Louros said.

The second is sensitivity. Because the group's binders are small peptides and the amyloid aggregates they target are large, traditional binding methods struggle with that mismatch, whereas FIDA resolves size changes close to the nanometre level.

"FIDA has a very high sensitivity, [it] can provide you changes close to the nanometer level for binding interactions," Dr. Louros said.

The group also uses FIDA for stability analysis of the different polymorphs, chemical and thermal stability and the maturation of the aggregates, to judge whether a redesigned fibril has been stabilised or destabilised.

Binding kinetics and complex patient samples

Beyond affinity, the lab uses the kinetics module, both for its own peptide binders and in collaborations with groups developing antibodies and nanobodies, at UT Southwestern and beyond.

"We very frequently use the kinetics module for those kinds of applications... we're also collaborating with other labs, both here at UT Southwestern and outside, who have also developed specific antibodies or nanobodies," Dr. Louros said.

Where Dr. Louros sees FIDA potentially standing out most is measuring binding in complex matrices, a long-standing difficulty for other methods, to test whether his binders have diagnostic potential directly against patient-derived material.

"Some of these binders that we are developing... [we're] trying to see if they have any potential diagnostic potential against patient samples, extracts from patients directly, which are in complex solutions pretty much," Dr. Louros said.

In practice that has meant trying brain extracts, plasma, serum and cerebrospinal fluid (CSF), alongside purified proteins, synthetic peptides and small compounds. Stickier or more clogging-prone samples need adapted protocols and washes, he noted, but that is manageable, helped by the instrument's quality-control dashboard.

What made it practical for a new lab

Assay development and onboarding are a major time sink for a young lab, and here ease of use is itself a capability: the instrument is quick to teach, so new people become autonomous fast, and because the readout is simple, those who understand it can adapt it to build new assays.

"It's super easy to use, which is again a big benefit for a new lab... it helps a lot to have a system that can be easily shown and taught to new people, and then they can pick it up and use it themselves very quickly," Dr. Louros said.

A platform that draws collaborators

That same ease, Dr. Louros added, is a reason FIDA earns its place in a new lab beyond the group's own projects: it attracts external collaborators who want to use it.

"It helps with setting up a lot of external collaborators that have an interest in using it. It's a very easy and quick to use instrument, so that's why it has an appeal to externals," Dr. Louros said.

What we learned from this conversation

Setting up a lab from scratch, Dr. Louros needed instruments that would let his group do ambitious science on a limited budget, and FIDA earned its place as one versatile platform the team uses across the work: checking that AI-designed proteins fold as intended, measuring how small peptide binders engage large amyloid aggregates, following the stability and maturation of different polymorphs, running binding kinetics with collaborators, and testing binders against real patient material such as brain extracts, plasma, serum and CSF. That it is inexpensive to run, quick to teach and appealing to collaborators is, for a new lab, part of the same story: one instrument doing the work of many while the lab finds its feet.

Curious how FIDA measures binding, size and stability in solution? Explore the FIDA technology and the Fida instrument, or browse the peer-reviewed literature. Read more scientists’ experiences with FIDA.