ScienceNot yet confirmed elsewhere1 publisher2 min readPublished
Cornell team reads cell metabolism from how fast NADH molecules rotate
Cornell researchers built a two-photon method that infers cell metabolism from the polarization of NADH fluorescence, reported Sept. 4 in Science Advances. The university says it could speed treatment screening, a use that hinges on how closely the simpler readout tracks lifetime imaging.
The Scientist · Science desk
What happened
- Optics specialist Warren Zipfel argued that lifetime imaging, or FLIM, suits repeated imaging poorly because the light exposure it needs is a serious stress on living cells.
- The new method, FPRM, scans polarized laser light across cells and splits the fluorescence into two detectors at once to gauge how fast NADH molecules rotate.
- Strongly polarized emission means slow rotation, which the team reads as more NADH bound to proteins, while freely rotating unbound NADH gives depolarized light.
- The instrumentation is simpler than FLIM's, but the data were hard to interpret and needed new analysis and calibration methods plus numerous control experiments.
Compiled by The ScientistSomething wrong?How this is made
Why it matters
- capability If the lower-light claim holds, light stress becomes less of a limit on how many times a lab can image the same living cell across an experiment.
- cost The simpler hardware shifts effort into analysis, and each adopting lab will likely need to repeat calibration and control work on its own microscope.
- constraint With both steps from polarization to energy production hedged, the ratio suits tracking change within cells over time better than assigning absolute metabolic states.
Ling's starting problem was timescale. "We want to look at cancer metabolism, but it's a very dynamic process. Everything can happen within minutes or hours, so there's not really a good way to track each cell's dynamics with the tools we had at that time," said Lu Ling, a former postdoctoral researcher who began the project in Claudia Fischbach's biomedical engineering lab at Cornell [4][5]. She and doctoral student Jack Crowley are co-lead authors [3]. Crowley took the project over when Ling left for a postdoc at the University of California, Berkeley [14].
Crowley described the design choice in two sentences. "This level of bias toward a polarized state is our readout in place of this photon timing experiment that takes much more complicated instrumentation," he said [16]. "It's a way to tell us similar information to what we could acquire using FLIM, but a lot faster with a lot less light," he added [17].
The claim rests on "similar information." The polarization ratio sits two inferences away from metabolism. Polarization indicates binding, and binding, in Cornell's wording, "might indicate energy generation in that part of the cell" [9]. Lifetime imaging is indirect too. Its photon delays report on the molecule's local environment and behavior [6]. The paper's title refers to NAD(P)H, a broader label than the NADH used throughout the announcement [13]. Ling's "minutes or hours" describes the pace of the biology she wanted to watch. The announcement does not report how closely the two readouts agreed on the same cells, how much less light the new method delivered, or how long any one cell was followed.
Two-photon microscopy is well suited to complex three-dimensional samples such as organoids and model organisms, and Crowley sees the method heading there [11]. "If you study cells in three-dimensional environments, they behave more like they do in the human body, or in the disease state that we try to model with our research," he said [15]. "So, any opportunity to provide new measurement strategies, especially ones that are simpler and lower cost, means that more people can envision diverse experiments that watch dynamic responses in intricate three-dimensional tissue-engineered structures" [12].
What to watch
- Whether the Science Advances paper shows a quantitative match between FPRM and FLIM readouts on the same cells, with the light dose each used.
- Whether a second lab reproduces the calibration on a different two-photon microscope.
- A drug-screening study that uses FPRM on cancer cells or organoids under treatment over hours.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence40
- Adoption
- Insufficient
- Hype gap+20
- Incentives55
- Confidence45
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Cornell researchers designed a new, faster form of two-photon fluorescence imaging for observing cell metabolism in real time.
- [2]
The findings were published Sept. 4 in Science Advances.
- [3]
The co-lead authors are former postdoctoral researcher Lu Ling and doctoral student Jack Crowley.
- [4]
"We want to look at cancer metabolism, but it's a very dynamic process. Everything can happen within minutes or hours, so there's not really a good way to track each cell's dynamics with the tools we had at that time,"
- [5]
Ling initiated the project while working in the lab of Claudia Fischbach, director of Cornell's Meinig School of Biomedical Engineering.
- [6]
FLIM, a common way of monitoring metabolism from NADH fluorescence, measures how long excited molecules stay excited before emitting light; the time delay of detected photons reveals information about the molecule's local environment and behavior.
- [7]
Warren Zipfel, associate professor of biomedical engineering who specializes in optical microscopy, argued FLIM was not ideal for correlating cell movement with metabolic changes because cells must be imaged at multiple time points over extended periods and too much light exposure is a serious stress for cells.
- [8]
In two-photon fluorescence polarization ratiometric microscopy (FPRM), a laser-scanning microscope scans polarized, focused light across cells and a polarizing beam splitter splits the fluorescence simultaneously into two detectors, giving a measure of how fast the emitting molecules rotate.
- [9]
Slower rotation, with highly polarized emission, indicates more NADH may be bound to proteins and therefore "might indicate energy generation in that part of the cell"; unbound NADH rotates more freely, with depolarized emission.
- [10]
FPRM instrumentation is not as complicated as FLIM instrumentation, but the experiments produced data that were challenging to interpret and required new analysis and calibration methods as well as numerous control experiments.
- [11]
Two-photon microscopy is well suited for imaging complex three-dimensional tissue systems, including organoids and model organisms.
- [12]
"So, any opportunity to provide new measurement strategies, especially ones that are simpler and lower cost, means that more people can envision diverse experiments that watch dynamic responses in intricate three-dimensional tissue-engineered structures."
- [13]
The paper is titled "Assessing cellular metabolic dynamics with two-photon NAD(P)H fluorescence polarization microscopy," Lu Ling et al, Science Advances (2026).
- [14]
Crowley took over the project when Ling left to continue her postdoctoral research at the University of California, Berkeley.
- [15]
"If you study cells in three-dimensional environments, they behave more like they do in the human body, or in the disease state that we try to model with our research,"
- [16]
"This level of bias toward a polarized state is our readout in place of this photon timing experiment that takes much more complicated instrumentation,"
ReportedInsufficientSource: Jack Crowley, quoted by phys.org2 sources— create a free account to open themView cited source - [17]
"It's a way to tell us similar information to what we could acquire using FLIM, but a lot faster with a lot less light."
ReportedInsufficientSource: Jack Crowley, quoted by phys.org2 sources— create a free account to open themView cited source - [18]
Cornell's announcement says the method could enable quicker screening of new therapeutic treatments.
ReportedInsufficientSource: phys.org (Cornell announcement)2 sources— create a free account to open themView cited source
Sources
1 independent publisher whose own reporting we read for this story.
- phys.orgFluorescent imaging tracks metabolism of cells in real time
1 article · October 9, 2026
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