You can watch what happens before disease strikes
For as long as science has sought to read the living brain, it has done so only by ending the life of the tissue it wished to understand. Researchers at Rice University have now crossed a quiet but profound threshold: a blood test called INTACT can monitor which genes are active in living brain tissue, in real time, without harm. Developed by Jerzy Szablowski's team and led in part by postdoctoral researcher Sho Watanabe, the system threads engineered molecular sensors through the bloodstream to catch the signals of thought, disease, and healing as they actually unfold. It is, in the oldest sense, a way of listening without disturbing the silence.
- Every existing method for reading gene activity in the brain requires destroying the very tissue being studied — a fundamental contradiction that has limited neuroscience for decades.
- INTACT breaks that constraint by pairing mRNA-hunting sensors with engineered bloodstream markers, allowing a simple blood draw to reveal which genes are firing inside a living brain.
- The system is programmable rather than custom-built gene by gene, meaning researchers can pivot to track Parkinson's, Alzheimer's, or any neural circuit simply by swapping in a target sequence.
- In early demonstrations, three distinct brain regions were monitored simultaneously in a living animal — a proof of concept that points toward tracking dozens of genes and organs at once.
- The team is already moving toward the next generation of the technology, with ambitions to extend cross-organ communication monitoring and bring a full 'omics revolution' into living tissue.
Inside every living cell, DNA is constantly being read — messenger RNA copies instructions from active genes, guiding the proteins that make cells do what they do. Knowing which genes are switched on at any moment could reveal how a body responds to medicine, how disease takes hold, how the brain changes over time. The problem has always been the same: to see that clearly, you had to destroy the tissue you wanted to study.
Bioengineers at Rice University have built a way around that. Their tool, called INTACT — In-vivo Tracking of Active Transcription — combines two innovations: engineered molecules called Released Markers of Activity, or RMAs, and sensors that seek out specific messenger RNA inside cells. When a sensor finds its target gene active, it triggers the release of RMAs into the bloodstream, where a blood draw can detect them. No tissue removed. No harm done.
What separates INTACT from techniques like next-generation sequencing or quantitative PCR is not just method but possibility. Those tools are powerful, but they require destroying the sample. INTACT works in a living organism, over time — before disease strikes, as it unfolds, and as treatments are applied. Postdoctoral researcher Sho Watanabe, who spent three years building the system, combined the two underlying technologies into something neither could achieve alone.
The elegance is in its programmability. Rather than engineering a custom reagent for every gene of interest, researchers simply include the target gene's sequence in the construct. In their demonstration, three separate brain regions were monitored simultaneously in an animal model. Lab director Jerzy Szablowski envisions scaling that to large numbers of genes, circuits, and eventually organs beyond the brain entirely.
Szablowski calls this step one. The first time gene transcription has been measured nondestructively in living tissue through a blood sample. His team is already working on what comes next.
Inside a living cell, DNA doesn't simply sit there. It gets read. Messenger RNA copies the instructions from active genes, and then that RNA guides the assembly of proteins—the actual workers that make a cell do what it does. If you could know which genes were switched on at any given moment, you could watch how a body responds to medicine, how it weathers environmental stress, how disease takes hold and progresses. Until now, the only way to see that clearly was to destroy the tissue you wanted to study.
Bioengineers at Rice University have changed that. They've built a blood test that reads gene activity directly from living brain tissue without harming it—a tool they call INTACT, short for In-vivo Tracking of Active Transcription. The test works by combining two recent innovations: engineered molecules called Released Markers of Activity, or RMAs, that Jerzy Szablowski's team pioneered, and sensors that hunt for specific messenger RNA inside cells. When those sensors find their target, they trigger the release of RMAs into the bloodstream, where a simple blood draw can catch them.
What makes this different from existing methods is fundamental. Techniques like next-generation sequencing and quantitative PCR have revolutionized how researchers study genes—they let scientists track many genes at once instead of studying them one by one. But both methods require destroying the sample. You can use them on tissue that's already been removed from the body, or on cells grown in a lab dish. INTACT works in living tissue, in a living organism, over time. You can watch what happens before disease strikes. You can see how gene expression shifts as illness unfolds.
Sho Watanabe, a postdoctoral researcher in Szablowski's lab and a lead author on the study, combined those two technologies to create something new. The elegance of INTACT lies in its flexibility. "You do not have to make a bespoke reagent for each and every one of these genes," Szablowski explained. "Instead, the targeting of genes is programmable." Want to track genes linked to Parkinson's? Alzheimer's? Specific neural circuits? You simply include the gene's sequence in the genetic construct. The system scales.
In their demonstration, the researchers showed they could monitor three different brain regions simultaneously in an animal model. That's just the beginning. Szablowski envisions a future where INTACT enables what he calls "highly multiplexed monitoring"—tracking large numbers of different genes, neural circuits, or brain regions all at once. The same approach could extend beyond the brain to other tissues entirely. Watanabe, who spent three years developing INTACT after earlier work studying how cells communicate through extracellular vesicles, is already planning his next project: using synthetic mechanisms to enable communication between different organs and areas of the body.
For now, INTACT represents a threshold moment. It's the first time researchers have measured gene transcription nondestructively in living tissue using a blood sample. That opens a door. Szablowski calls this step one. "In the future, we want to make this omics revolution possible in living tissue," he said. "We are already working on the next ones."
Notable Quotes
You do not have to make a bespoke reagent for each gene—instead, the targeting of genes is programmable— Jerzy Szablowski, Assistant Professor of Bioengineering at Rice University
In the future, we want to make this omics revolution possible in living tissue. This is the first step, and we are already working on the next ones— Jerzy Szablowski
The Hearth Conversation Another angle on the story
Why does it matter that you can do this without destroying tissue?
Because you can follow the same organism over time. You see what's happening before disease, during disease, after treatment. You're not comparing different samples—you're watching one story unfold.
So this is really about tracking disease progression?
That's one use. But it's also about understanding how the brain responds to anything—a drug, an injury, learning, stress. Any change in what genes are active tells you something.
The blood test part—how does that work exactly?
Sensors in the brain tissue detect the messenger RNA you're interested in. When they find it, they trigger the release of these marker molecules into the bloodstream. You draw blood, you find the markers, you know that gene was active.
And you can do this for multiple genes at once?
Right now they showed three brain regions. But the design is scalable. In theory, you could program it for dozens of genes, different circuits, different tissues.
What's the practical difference from existing gene-tracking methods?
Existing methods destroy what you're studying. You can only use them on tissue that's already been removed. This works in a living brain, in a living person potentially, without harm.
So this could change how we diagnose or monitor neurodegenerative disease?
Completely. Instead of waiting for symptoms to get worse, you could see gene expression changes in real time. You'd know if a treatment is working at the molecular level before you see clinical improvement.