He put a working laser inside a living cell. Then he gave it a barcode - and built a company around the readout.
Biomedical engineer · Columbia · MIT · Mass General · Boston, MA
The quiet guy with lasers in his pocket
Flow cytometry tells you what a cell is. Sheldon Kwok wants to tell you what it does next.
Start with the strange part. Inside the cells Sheldon Kwok works with, there is a laser. Not a metaphor for one - an actual microscopic cavity that, when nudged with light, emits a clean beam of its own. Each one is tuned to a slightly different infrared wavelength, somewhere between 1,170 and 1,580 nanometres, far past anything a human eye can register. One cell, one color, one barcode. Do that across millions of cells and you have given an entire population individual names.
That is the engine of LASE Innovation, the Boston-area company Kwok runs as CEO and co-founded in 2019. The idea did not arrive in a pitch deck. It arrived as his doctoral thesis at MIT, supervised by Prof. Seok-Hyun (Andy) Yun, the physicist who would become his co-founder. The two spun the lab work out of Massachusetts General Hospital and MIT and turned a peculiar piece of photonics - the LASE Particle, or LP - into a product line.
The point of the barcode is not novelty. It is time. Conventional flow cytometry, the workhorse of immunology, is brutal in its efficiency: a cell streams past a laser, scatters its signal, and is read once. You learn what the cell is at that instant and then it is gone, mixed back into the slurry or destroyed. Kwok's particles change the contract. Because each cell carries a permanent, readable tag, you can run the same population through the machine again - and again - and match every reading back to the individual it came from. LASE calls the result Multi-pass flow and Time-lapse flow cytometry. The plain-English version: a movie of single cells, where there used to be a snapshot.
That sentence is the whole thesis of the company, compressed. Immunology has spent decades getting better at the snapshot - more markers, more colors, higher dimensions. But an immune response is a story that unfolds over hours and days, and a snapshot cannot tell you which cell did what next. Kwok's bet is that the missing axis is time, and that the way to add it is to stop throwing cells away after the first look.
The path here was unusually long for a founder. Kwok studied Chemical Physics at Columbia, graduating in 2012 with honors in chemistry. He then entered the Harvard-MIT MD-track program, the kind of training that produces clinicians. He chose the laser instead. His PhD, completed in 2019 in Medical Engineering and Medical Physics, was built around making semiconductor microcavities small enough, stable enough, and biocompatible enough to live inside a cell without killing it - silica-coated, single-mode, sub-nanometre in linewidth. The work landed in Nature Photonics in 2020 under the title "Wavelength-encoded laser particles for massively multiplexed cell tagging," with Kwok among the authors.
It is worth sitting with how counterintuitive the object is. A laser is a thing we associate with optics benches and warning signs. Shrinking one to ride inside a T cell, getting it to lase reliably, and then reading thousands of them as they flow past a detector is closer to engineering than biology - which is precisely why an engineer ended up running the company.
Kwok is careful about where the value sits, and it is not only in the cytometer on the bench. The deeper asset is the data the barcodes produce: the same cell, measured repeatedly, across conditions and across time. That is a kind of dataset biology has rarely had at scale, and it happens to be exactly the kind of input the new generation of AI and machine-learning cell models are hungry for. A model that wants to predict how a cell will respond needs examples of cells actually responding, tracked as individuals. LASE's barcodes generate that.
The commercial story has grown up around that thesis. The company has raised more than $9 million, expanded its leadership with a chief commercial officer, won an SBIR award to study T-cell function over time, and in 2025 teamed with Talon Biomarkers on a first-of-its-kind service to read T-cell activation kinetics at single-cell resolution. The pattern is consistent: turn the strange physics into a service a working lab can actually buy.
For a technology this exotic, Kwok's framing is notably modest. He does not pitch lasers as spectacle. He pitches them as a better way to take attendance - to know, out of millions of cells, which one is which, and to keep knowing across the length of an experiment. The spectacle is incidental. The attendance is the product.
Run the company forward and the ambition is plain: give every laboratory access to high-dimensional, time-resolved single-cell data, not just the well-funded few with the biggest instruments. Fewer colors, more markers, repeat reads, individual identity preserved - the LASE Particle is a small object aimed at a large rearrangement of how single-cell biology gets done. Whether it becomes standard equipment or a specialist's tool, the underlying move is the same one Kwok made as a graduate student: refuse to accept that you only get to look at a cell once.
Spinouts die in the gap between a Nature paper and a thing a customer can use without a physics PhD on staff. Kwok's answer has been to package the science as services and instruments rather than as a manuscript. The flagship is the LASE Cytometer, the machine built to read the particles; around it sit the methods - Multi-pass flow, Time-lapse flow - and the partnerships that put them to work. The 2025 collaboration with Talon Biomarkers is the clearest example, pairing LASE's barcoding with Talon's biomarker workflows to deliver T-cell activation kinetics as a service a lab can simply order. An SBIR award funding the study of T-cell function over time pushes in the same direction: prove the time axis matters in the place immunologists already care about most.
The particles attach to cells through biotin-streptavidin binding, one of the most reliable handshakes in biochemistry, which is part of why the approach is plausible rather than merely clever. There is a difference between a demonstration and a tool, and most of a founder's life is spent crossing it. Kwok has kept the company small and specialized - roughly a dozen people spanning biology, chemistry, scientific operations, engineering, and finance, working out of Waltham, Massachusetts - while it does that crossing.
What he tends not to do is oversell. Speaking at the BIO International Convention's Start-Up Stadium, the pitch was framed around solving complex life-science challenges, not around the visual drama of lasers inside cells. The restraint is telling. The technology is genuinely strange; the value proposition is almost boring by design - measure your cells more than once, and keep track of which is which. That gap between exotic means and pragmatic ends is exactly where Kwok seems most comfortable.
That is the through-line from Columbia to MIT to a building in Waltham, Massachusetts. A founder who trained to read patients chose instead to read cells - one barcode, one wavelength, one frame of the movie at a time.
EACH BAR = ONE WAVELENGTH = ONE CELL'S NAME
A silica-coated semiconductor microcavity attaches to a cell. When light hits it, it lases - emitting a single, sharp infrared wavelength unique to that cell.
The cell flows past a detector. Instead of one destructive snapshot, the barcode lets the same cell be measured again on a later pass - Multi-pass flow.
Match every reading back to the individual cell it came from, across time and conditions. The output is a movie of single cells, not a still frame.
A key challenge in our understanding of immune function is the ability to track individual cell responses at scale.- Sheldon Kwok, on why a snapshot was never going to be enough
Graduates with a B.A. in Chemical Physics, honors in chemistry. The physics-of-molecules foundation that the later work would lean on.
Begins PhD research under Prof. Seok-Hyun (Andy) Yun, building laser particles small and stable enough to live inside cells.
Completes his doctorate in Medical Engineering and Medical Physics and co-founds LASE Innovation with Yun, spinning the lab out into a company.
Co-authors "Wavelength-encoded laser particles for massively multiplexed cell tagging." The Series A round lands.
Multi-pass flow and Time-lapse flow cytometry published; Trevor Brown joins as Chief Commercial Officer.
Launches a first-of-its-kind service to read T-cell activation kinetics at single-cell resolution.