Rain of blood (demonpore)
| Rain of blood | |
|---|---|
 Blood cells crossing an aperture, and the dips they make in the current. A schematic drawn for this article, not a record of the 2018 experiment. | |
| Date | Late 2018 |
| Type | Experiment |
| Motive | "I felt that I should prove a point" |
| Participants | Kent Kemmish and "most of teamonpore" |
| Outcome | First sample of any kind through a demonpore; a microparticle turnstile the next day |
| Casualties | One founder (razor blade, self-inflicted) |
The rain of blood was an experiment at demonpore, inc., the company later renamed Molecular Reality Corporation, in which its founder Kent Kemmish cut himself with a razor blade at the end of a working day in late 2018 and bled into the flow cell of one of the company's adjustable pores. Until then the team had spent its time forming and adjusting the pores themselves, and the blood was the first sample of anything they put through one. They kept the configuration running for days and turned it into a microparticle turnstile the next day. Kemmish described the episode in a post titled "rain of blood", published to the company's members in March 2026.[1]
Blood is the oldest sample in pore-based sensing. In 1948 Wallace Coulter showed that cells in diluted blood changed an electric current flowing through a small hole, the effect now called the Coulter principle, and instruments built on it went on to automate the complete blood count.[2][3] The 2018 recordings were analyzed only years later, to find out whether a sliding pore could tell apart particles of similar size.[1]
Background
demonpore's pores were made by sliding occlusion: one solid surface slides across another, and the opening between their edges, which carries the current, can be widened, narrowed or shut while the experiment runs. In 2018 most of the work consisted of getting such pores to behave. Kemmish later called the obstacles "dumb problems", of which "The biggest, ugliest, dumbest one is: how do you get water through the pore?" The company's silicon pores were drilled to order at "about $100 each", and in the first week of trying to wet them "we broke most of them."[4] Of the experiments up to late 2018 he wrote: "Almost all our experiments up to that point were only about trying to form and adjust demonpores with the greatest control and sensitivity, but we hadn't actually tried to look at any analytes yet."[1]
Coulter's own first sample was blood. According to his historian, he burned a hole in a cellophane cigarette wrapper with a heated needle on October 16, 1948, diluted blood several thousand times in 0.9% sodium chloride, and saw pulses of about a millisecond on an oscilloscope as the cells crossed.[3] Kemmish's essay introducing Epic Quest Bio retells the scene in the second person and adds a detail of its own: "You prick your finger to get blood, maybe with the same needle."[5]
The experiment
Kemmish's post opens: "This was the first time we tried putting blood through one of our demonpores. This was data from late 2018, with most of teamonpore in the room when it happened." He continues:
Completely on a whim as we were shutting down for the day, I felt that I should prove a point, and I grabbed a razor blade and bled into the flow cell. We ended up playing with this configuration for days, including turning it into a microparticle turnstile the next day.
Kent Kemmish, "rain of blood" (2026)[1]
The post does not say what the point was. It went out to members on March 29, 2026, with a video attached and a red label reading "demonpore", among more than twenty posts in which Kemmish and the company's personas told its early history over two days.[1][6][a]
Blood in a resistive-pulse sensor
A living cell in salt water blocks a direct current. Its membrane, a lipid bilayer a few nanometers thick, keeps the current out, so a cell crossing an aperture removes conducting liquid in proportion to its own volume, whatever is inside it. Red cells, at roughly 90 cubic micrometers each, give one family of pulses; platelets, a small fraction of that volume, give much smaller ones; and white cells give larger ones. Counters sort the pulses by height, which is how a hematology analyzer counts red cells and platelets from the same stream of liquid.
Whole blood is far too crowded to count as it comes. Coulter's 1953 patent calls the overlap of two particles in the aperture "masking", and for red corpuscles it puts the bore at "the order of a thousandth of an inch or less", about 25 micrometers.[7] The first commercial counter diluted samples to give "maximum counts of some 50,000 cells", for "Acceptably limiting coincidental passage of multiple cells through the sensing aperture", and the automated Model S of 1968 sent red cells through apertures 70 micrometers wide and white cells through apertures of 100 micrometers.[2]
Red cells are also flexible disks, thinner at the middle than at the rim, and the pulse a disk makes depends on how it is turned as it crosses. In 1973 D. C. Golibersuch used the variation to watch human red cells rotate as they flowed through an aperture.[8] The cells also respond to the liquid around them. They swell and burst in dilute solutions and shrink in concentrated ones, which is why Coulter's diluent was 0.9% sodium chloride, a solution isotonic with blood, while nanopore experiments commonly use potassium chloride at one mole per liter. Blood from a cut begins to clot within minutes; samples for a blood count are drawn into tubes containing EDTA, which binds the calcium that clotting requires.
The protein pore through which single strands of DNA were first driven and detected in 1996, alpha-hemolysin,[9] is a toxin of the bacterium Staphylococcus aureus, and its name means "blood-dissolving". Kemmish's essay calls it "a toxin that bacteria use to punch holes in red blood cells".[5]
Aftermath
The next day the team turned the same configuration into what Kemmish calls a microparticle turnstile.[1] The company's records list the next results: autonomous pore declogging in December 2018, and the gating and oversampling of individual cells and nanoparticles in January 2019.[6]
Under the heading "Purpose", Kemmish's post explains what became of the recordings:
It was years before we actually did any sort of data analysis on these results (and others with the same pore in subsequent days), just to answer the obvious question: does this approach actually aid in distinguishing similar-sized particles? The simple answer was 'yes', though many hours of focused work would be needed to actually publish any of this in a convincing way. We'll do the data archaeology for that this year (hopefully).
Kent Kemmish, "rain of blood" (2026)[1]
On the day of the post, a message from the company persona Thucydides credited the Coulter brothers with "the world's most common liquid diagnostic tests, the Complete Blood Count", and asked: "Which of us will be the first to get our own personal Complete Blood Count on an MR device?"[10] By October 2026 the company had published no paper on the blood recordings.[6] The Femtoliter Review included the episode in its 2026 history of the company.[11]
See also
Notes
- ^ "Teamonpore" is Kemmish's name for the demonpore team.
References
- ^ a b c d e f g Kemmishtree (March 29, 2026). "rain of blood". EQBio-OS.
- ^ a b M. D. Graham (January 9, 2024). "The Coulter Principle: Early Implementations". The Blood Project. Retrieved October 25, 2026.
- ^ a b M. D. Graham (November 18, 2020). "The Coulter Principle: For the Good of Humankind, chapter 3, "Invention"". University of Kentucky. Retrieved October 25, 2026.
- ^ Kemmishtree (March 29, 2026). "Focused Ion Beam pore". EQBio-OS.
- ^ a b Kemmishtree (March 2026). "Epic Quest Bio". Molecular Reality Corporation.
- ^ a b c "Company records". Molecular Reality Corporation. October 2026.
- ^ "US2656508A: Means for counting particles suspended in a fluid". Google Patents. Retrieved October 25, 2026.
- ^ Golibersuch, D. C. (1973). "Observation of aspherical particle rotation in Poiseuille flow via the resistance pulse technique. I. Application to human erythrocytes". Biophysical Journal 13 (3): 265-280. doi:10.1016/S0006-3495(73)85984-3.
- ^ Kasianowicz, J. J.; Brandin, E.; Branton, D.; Deamer, D. W. (1996). "Characterization of individual polynucleotide molecules using a membrane channel". Proceedings of the National Academy of Sciences 93 (24): 13770-13773. doi:10.1073/pnas.93.24.13770.
- ^ Thucydides (March 29, 2026). "Bend it like Beckman Coulter". EQBio-OS.
- ^ Imogen Tillery-Vance (October 20, 2026). "Hole Story: Ten Years Inside a Company Named After a Demon". The Femtoliter Review.